Joshua Driggs v. Andrew T.G. Howlett, M.D., et ux ( 2016 )


Menu:
  •                                                                            FILED
    MARCH 8, 2016
    In the Office of the Clerk of Court
    WA State Court of Appeals, Division III
    IN THE COURT OF APPEALS OF THE STATE OF WASHINGTON
    DIVISION THREE
    JOSHUA DRIGGS, a single man,                   )
    )         No. 32381-1-111
    Appellant,                )
    )
    v.                                      )
    )
    ANDREW T.G. HOWLETT, M.D. and                  )         UNPUBLISHED OPINION
    JANE DOE HOWLETT, and their marital            )
    community, PROVIDENCE PHYSICIAN                )
    SERVICES CO. aka Providence                    )
    Orthopedic Specialties, a Washington           )
    Corporation,                                   )
    )
    Respondents.              )
    FEARING, J. -This appeal primarily asks us to address conditions precedent to a
    medical expert rendering opinions during a medical malpractice trial. The trial court
    excluded opinions of plaintiff Joshua Driggs' foremost medical expert because the
    physician did not commit, when asked, to base opinions on reasonable medical
    probability, because he testified to a national standard of care, because he conceded in
    cross-examination that his opinions were personal, and because he did not provide a
    percentage for the increased risk of a fracture resulting from the lack of fixation for an
    allograft. We agree with Driggs that the trial court committed harmful error, and we
    remand for a new trial.
    No. 32381-1-111
    Driggs v. Howlett, MD.
    FACTS
    Joshua Driggs sues Providence Physician Services and its employee, Dr. Andrew
    Howlett. We refer to the respondents collectively as Providence Physician Services or
    Providence.
    Appellant Joshua Driggs asserts errors during the course of trial. Therefore, we
    briefly outline the facts in this section of the opinion and later provide extended details of
    the facts when reviewing trial rulings. Joshua Driggs limits his suit for medical
    malpractice to claims of negligence by two employees of Providence Physician Services,
    Orthopedist Andrew Howlett and Physician's Assistant Brandi DeSaveur, during 2009.
    The story of Driggs' medical care begins earlier.
    In 2004, health care professionals diagnosed fifteen-year-old Joshua Driggs with
    osteosarcoma above the ankle in his right distal tibia. Osteosarcoma is a common form
    of bone cancer in children. Instead of amputating the leg, Dr. Ernest Conrad removed the
    cancerous fragment of the bone and inserted an allograft, or bone segment from a
    cadaver. Dr. Conrad attached the allograft to the remaining tibia by screwing a metal
    plate to the tibia and allograft. The plate supports the allograft because the cadaver bone
    lacks the strength of a living bone. The metal plate is called fixation or hardware and
    serves as a support for the allograft. In this suit, Joshua Driggs and his experts promote
    the need of fixation to an allograft.
    The cadaver bone inserted into Joshua Driggs' tibia extended six and a one-half
    2
    No. 32381-1-111
    Driggs v. Howlett, MD.
    centimeters, which equates to three and one-half to four inches. Driggs' surgeon, Dr.
    Ernest Conrad, would not remove the metal plate from a patient's allograft without
    substituting another plate or other form of fixation unless the graft is "very small" and
    has vigorous growth around it. Conrad defines "very small" in this context as "four or
    five centimeters or smaller." Clerk's Papers (CP) at 1552.
    Although properly aligned initially, Driggs' allograft later twisted and required
    additional surgery. In January 2006, Dr. Andrew Howlett, of Providence Physician
    Services, assumed care of Joshua Driggs' right leg. In January 2006, Dr. Howlett
    performed an ankle fusion and osteotomy on Driggs to correct malalignment in the leg,
    improve mechanics in the foot, and decrease arthritic pain. In November 2006, Dr.
    Howlett performed another surgery to alleviate pain in the ankle caused by two screws.
    In January 2008, Joshua Driggs' right ankle pain returned. Dr. Andrew Howlett
    discussed with Driggs another surgery to remove the plate inserted by Ernest Conrad and
    replace it with an intramedullary rod. A rod may substitute for a plate in supporting the
    allograft. According to Howlett, he discussed with Driggs, before the surgery, the
    possibility of not replacing the plate with a rod, because of deleterious effects of a rod.
    An intramedullary rod runs through the inside of the bone, and the rod's installation
    requires destruction of existing allograft and live bone.
    During a March 6, 2009 surgery, Dr. Andrew Howlett removed the plate and
    screws from Joshua Driggs' cadaver bone. Dr. Howlett did not replace the plate with an
    3
    No. 32381-1-111
    Driggs v. Howlett, MD.
    intramedullary rod. Driggs claims Dr. Howlett violated the standard of care by failing to
    install fixation and breached his right to informed consent by failing to explain the risk to
    him of the omission of fixation.
    After the March 2009 surgery, Joshua Driggs underwent physical therapy, but
    continued to suffer pain and swelling. In May, while crossing his yard, Driggs
    experienced a shooting pain in his right leg.
    On May 27, 2009, Joshua Driggs visited Dr. Howlett's office at Providence
    Physician Services and met with Physician's Assistant (PA) Brandi DeSaveur. Driggs
    reported the increased pain and swelling to DeSaveur. PA DeSauver X rayed the tibia
    and diagnosed a possible sprain. DeSaveur failed to note a subtle fracture. Driggs
    contends that DeSaveur violated the standard of care by failing to identify the fracture
    and Andrew Howlett violated the standard of care by failing to properly supervise Brandi
    DeSaveur. Driggs posits that his condition worsened as the result of the failure to
    promptly diagnose the fracture. On May 27, DeSaveur instructed Driggs to discontinue
    physical therapy for one week.
    On June 7, 2009, Joshua Driggs visited a hospital emergency room due to pain in
    his right leg. He received a shot and a prescription for pain medication. On June 8,
    Driggs returned to Dr. Andrew Howlett's office. During the appointment, Howlett
    X rayed Driggs' tibia and noticed the bone fracture.
    On June 11, 2009, Dr. Andrew Howlett performed another surgery and inserted a
    4
    No. 32381-1-111
    Driggs v. Howlett, MD.
    tibial intramedullary rod into Joshua Driggs' right lower leg. Despite the rod, the cadaver
    bone failed to fuse with Driggs' live bone.
    On December 11, 2009, Dr. Howlett, during another surgery, placed a rod with
    intermittent screws through the entire tibia. The December 2009 surgery necessarily
    destroyed Driggs' subtalar joint in his ankle. The surgery also caused equinas, a
    condition by which Driggs' toes touch the floor but his heel rests two and one-half inches
    above the floor. Driggs thereafter walked on his right toes.
    In July 2010, Dr. Brian Padrta performed an operation to remove two remaining
    screws and correct the equinas. Nevertheless, as of March 25, 2013, Driggs continued to
    suffer from severe equinas, numbness in his right foot, and a limp.
    PROCEDURE
    On January 17, 2012, Joshua Driggs sued Dr. Andrew Howlett and his employer,
    Providence Physician Services. Driggs asserted professional negligence and lack of
    informed consent. The complaint alleged:
    2.8 On May 27, 2009, JOSHUA DRIGGS returned to DR.
    HOWLETT'S office with onset of right ankle pain and swelling. X-rays
    were taken and read as negative for fracture.
    2.9 On June 7, 2009, JOSHUA DRIGGS went due [sic] to Sacred
    Heart Medical Center due to extreme pain in his right lower extremity.
    Images obtained showed an insufficiency fracture.
    2.12 JOSHUA DRIGGS suffered an insufficiency fracture in his
    right lower extremity as a result of DR. HOWLETT'S failure to install an
    intramedullary rod or other stabilization when he removed JOSHUA
    DRIGGS' medial compression plate on March 9, 2009.
    5
    No. 32381-1-111
    Driggs v. Howlett, MD.
    3.6 The Defendants, ANDREW T.G. HOWLETT, M.D. and JOHN
    DOE, breached their duties owed to JOSHUA DRIGGS by failing to
    inform JOSHUA DRIGGS of the relative material risks of removing the
    stabilization hardware in his allogra[ft] and not replacing it.
    3.7 Defendants PROVIDENCE PHYSICIAN SERVICES CO. was
    independently negligent and negligent by and through the acts and/or
    omissions of defendant Dr. ANDREW T.G. HOWLETT, M.D. in their
    capacities as employees, agents, principals, partners, shareholders, corporate
    officers, directors and/or members of defendants PROVIDENCE PHYSICIAN
    SERVICES CO.
    CP atl0-11, 13-14. The complaint did not specifically identify Physician's Assistant
    Brandi DeSaveur as a negligent actor. In their answer to the complaint, Dr. Andrew
    Howlett and Providence Physician Services admitted that Providence employed Dr.
    Howlett, Howlett acted within the scope of his employment when treating Driggs, and
    Providence was vicariously liable for any negligence committed by Howlett.
    Both parties engaged expert medical witnesses. Joshua Driggs hired two
    witnesses, Ors. Steven Graboff and Lawrence Menendez. Providence engaged five
    experts, but only Ors. James Bruckner and Brian Padrta testified at trial.
    On May 3 and September 20, 2013, Joshua Driggs deposed Dr. Andrew Howlett.
    Driggs' counsel addressed, with Howlett, Brandi DeSaveur' s failure to diagnose the tibia
    fracture on May 27, 2009. A portion of the September deposition of Dr. Howlett follows:
    Q. And did Brandi DeSaveur have an occasion to interpret an x-ray
    that was taken, I believe, on May 27th, 2009?
    A. If that would be the day that she was in clinic, I-that would-
    more than likely, that was the day that she got an x-ray.
    6
    No. 32381-1-III
    Driggs v. Howlett, MD.
    Q. And she did not recognize the start of a fracture in the x-ray,
    correct?
    A. It was a very subtle finding at that time. Correct.
    Q. It's something that you recognized immediately when you
    reviewed the x-ray, correct?
    A. I don't remember the exact time when I reviewed the x-ray and
    what I stated to her at that time.
    Q. You were the one, when you reviewed the x-ray, that determined
    that the fracture had been missed, correct?
    MR. KING: Object to the form as to the word "missed," but you
    may go ahead and respond.
    A. I recognized the fracture upon reviewing the x-rays.
    Q. (BY MR. SWEETSER) Do you agree that Brandi DeSaveur's
    failure to timely identify the fracture led to the wrong instructions to the
    patient to continue to weight bear and participate in physical therapy?
    MR. KING: Object to the form. You may respond.
    A. Yeah, I think, at that time, if she had recognized the fracture, we
    probably would have changed our postoperative protocol at that time.
    CP at 1270-71.
    The parties filed proposed jury instructions and a trial management report weeks
    before a January 6, 2014 trial. On December 9, 2013, Joshua Driggs proposed a jury
    instruction that declared Brandi DeSaveur to be an agent of Providence and any act or
    omission ofDeSaveur was an act or omission of Providence. On December 12, 2013,
    Driggs filed a joint trial management report, which read in part: "[The Plaintiff also
    contents [sicJ that Dr. Howlett and coemployees failed to follow the standard of care in
    their follow up treatment under the circumstances. (The Defendant objects to this
    statement.)]." CP at 112 (alterations in original). The trial management report did not
    name Brandi DeSaveur as a coemployee who breached the standard of care.
    7
    No. 32381-1-111
    Driggs v. Howlett, MD.
    Joshua Driggs' feature witness, Dr. Lawrence Menendez, has served on the
    University of Southern California Keck School of Medicine staff since 1985. He
    specializes in the care of bone tumors. He teaches orthopedic oncology to medical
    students. He has been board certified since 1987. Menendez is a member of the
    American Academy of Orthopedic Surgeons, Musculoskeletal Tumor Society, and
    International Society on Limb Salvage and sometimes lectures at the respective
    organizations' meetings.
    Dr. Lawrence Menendez could not attend trial to testify. On December 12, 2013,
    Joshua Driggs conducted a video recorded perpetuation deposition of Menendez to play
    to the jury. Near the beginning of Dr. Lawrence Menendez's deposition, Joshua Driggs'
    counsel remarked and asked:
    Q And, Doctor, again, I want you to base your opinions on
    reasonable degree of medical certainty based upon what's more likely than
    not likely as I ask you questions about your opinions in this regard.
    Did you have a chance to look at X-rays after the surgery in March
    of2009?
    A Yes.
    CP at 1347. Note that Dr. Menendez did not respond to counsel's direction to base his
    opinions on reasonable medical certainty.
    During the deposition, Dr. Lawrence Menendez spoke about failings of allografts
    from weakness and incapacity to incorporate into the host bone. He promoted the need to
    affix an allograft with plates and screws to promote strength in the allograft. He
    8
    No. 32381-1-111
    Driggs v. Howlett, MD.
    commented on holes or weak areas in the allograft called stress risers, which fracture
    without protection from hardware. Dr. Menendez testified that
    when you take the hardware out, for whatever reason it might be,
    you generally want to minimize the risk of fracture ... you want to put
    something back in ... you want to protect it so that you minimize the risk
    of fracture.
    CP at 1343.
    During his deposition, Dr. Lawrence Menendez testified that in 2009 the national
    standard of care for removing fixation from an allograft required replacement of the
    fixation. Joshua Driggs then questioned Dr. Menendez about whether a fracture will
    result from the lack of fixation:
    A Yes.
    Q Okay.
    Is there a national standard of care with regards to removing a plate
    or a fixation of this nature, 2009, as to what you should do with regards to
    supporting the allograft-this allo--type of allograft?
    MR. KING: Objection ....
    BYMR. CASEY:
    Q Go ahead and answer, Doctor, as to the national standard of care.
    Is there a national standard of care?
    A Well, the majority of people who use allografts on a routine bases
    are generally very concerned about protecting the allograft because of the
    problems that result when you don't. So in my experience and based on,
    again, presentations, reading and so forth, that it would be very unusual to
    not put fixation back into the allograft. That is, to leave it bare is risky.
    MR. KING: Move to strike as being nonresponsive ....
    BY MR. CASEY:
    Q Okay. I'll reask it, Doctor.
    9
    No. 32381-1-III
    Driggs v. Howlett, MD.                                     •
    Basically, Doctor, is there, nationally, a standard of care with
    regards to replacing or as to what you do if you're going to be removing
    fixation from a patient, 2009, similar to this type of hardware?
    MR. KING: Same objection.
    THE WITNESS: So the standard of care is to put fixation in.
    BYMR. CASEY:
    Q Is that a national standard?
    MR. KING: Same objection ....
    BY MR. CASEY:
    Go ahead, Doctor.
    A Yes.
    Q What was that?
    A Yes.
    Q And when you say "put fixation in," what do you mean?
    A I mean, to put in, in the case of long, structural allografts, either a
    plate and screws or a rod, metal rod, that's also affixed with screws.
    Q And, Doctor, again, I want you to base your opinions on
    reasonable degree of medical certainty based upon what's more likely than
    not likely as I ask you questions about your opinions in this regard.
    Did you have a chance to look at X-rays after the surgery in March
    of2009?
    A Yes.
    Q Doctor, do you have an opinion, based upon what's more
    probable than not-more likely than not as to whether or not had there been
    a rod placed, it would not have fractured when it did?
    MR. KING: Same objection.
    Go ahead, Doctor.
    THE WITNESS: So if you put internal fixation in in a form of a
    rod, there's a likelihood that the allograft will fracture.
    So it's less likely that you'll get a fracture if you put fixation in to
    support the allograft. If you don't put fixation in, it's more likely that
    you' 11 have a fracture for the reasons I discussed earlier.
    CP at 1343-47, 1350-51.
    10
    No. 32381-1-III
    Driggs v. Howlett, MD.
    Providence Physician Services also questioned Dr. Menendez during the
    perpetuation deposition:
    Q No. My question is: The opinions you've expressed here today in
    response to my questions and Mr. Casey's questions are simply your
    personal opinions?
    THE WITNESS: Well, I mean, technically, I'm offering my opinion
    ... based on my knowledge and expertise and education and experience,
    but I haven't given you a specific article or pieces of literature, anything of
    that nature. So technically, it's my opinion, yes.
    CP at 1411.
    On December 20, 2013, Providence Physician Services moved to exclude
    evidence of the circumstances leading to Providence's termination of Brandi DeSaveur.
    In response, Joshua Driggs commented that evidence established that DeSaveur should
    have, but failed to, discern fractures present on the May 27, 2009 X ray, and, as a result,
    Driggs' fractures worsened and complicated his treatment.
    On December 31, 2013, Providence Physician Services filed a supplemental
    motion in limine to preclude testimony by Dr. Lawrence Menendez regarding the
    standard of care, medical causation, and medical risk for informed consent. Providence
    I
    underscored that Dr. Menendez is from California and he testified, during his deposition,
    to a "national standard of care" rather than a Washington standard of care. Joshua Driggs
    responded that an out-of-state expert may testify to the national standard of care as long
    as other evidence shows the standard of care in Washington to be a national standard.
    I
    11
    l
    t
    f
    !
    Ii
    No. 32381-1-III
    Driggs v. Howlett, MD.
    Driggs submitted a declaration by Dr. Menendez stating that he conferred with experts
    within Washington and determined that the Washington standard of care was equivalent
    to the national standard. In response, Providence argued that submission of a
    supplemental declaration amounted to an ambush, did not allow for cross-examination,
    was inadmissible, and should not be considered by the trial court when ruling on its
    motion. The trial court agreed with Providence's characterization of the declaration as an
    "ambush" and refused to consider it. After hearing the parties' arguments on January 2,
    2014, the court reserved ruling on the motion.
    On January 7, 2014, Joshua Driggs began presenting his case to the jury. That
    day, Driggs submitted to the court an affidavit from Dr. Lawrence Menendez averring
    that he contacted medical colleagues in the state of Washington to confirm that the
    practices in Washington echoed the national standards of the American Orthopedic
    Association, that the standard of care applicable in this case is a national standard, and
    I
    that he is aware of the standard of care in Washington.
    On January 9, 2014, orthopedic surgeon Steven Grabofftestified at trial as an
    expert for Joshua Driggs. When Dr. Grabo ff first sought entry into medical school, no
    United States school admitted him. He, therefore, began medical school in Guadalajara,
    Mexico. After four years and three months of schooling in Mexico, Graboff transferred
    to the University of California at Irvine School of Medicine, where he received a medical
    degree in 1980. Grabo ff is also board certified, although, according to Graboff, he has
    12
    No. 32381~1-III
    Driggs v. Howlett, MD.
    encountered difficulty on occasion in retaining certification. Dr. Graboff is not a
    specialist in tumors, but has experience with limb salvage through allografts. The
    American Academy of Orthopedic Surgeons suspended Graboff for two years for
    testimony he gave in a medical malpractice suit.
    Dr. Steven Graboffs trial testimony included:
    Q Okay. Do you have-do you know whether the national standard
    of care and the Washington state standard of care is any different?
    A I do know that the standard of care here is the same as the
    national standard of care.
    Q What's your understanding of his [James Bruckner's] testimony?
    A My review of Dr. Bruckner's testimony is that he stated in his
    deposition that the Washington standard is a national standard. It's no
    different than anywhere else.
    Q You verified that with other orthopedic doctors in the state of
    Washington?
    A I did.
    Q Okay. Are you familiar then with the national standard and the
    standard of care in the state of Washington?
    A lam.
    3 Verbatim Report of Proceedings (VRP) (Jan. 9, 2014) at 376-77. Dr. Grabofflater
    testified that a physician violates the standard of care if he does not replace fixation for an
    allograft with other fixation.
    Concerning the care provided by Physician Assistant Brandi DeSaveur, Dr. Steven
    Grabo ff testified:
    Q Okay. And, Doctor, I want you to assume there's been testimony
    yesterday that a Ms. Desaveur was the one that interpreted the May 27th x-
    ray, and you've had a chance to review that?
    13
    I
    i
    No. 32381-1-111
    Driggs v. Howlett, MD.
    A Yes.
    Q Do you have an opinion as to whether or not there was, from an
    orthopedic standpoint, a violation that the standard of care as to the
    interpretation of that?
    MR. KING: Your Honor, may we approach?
    THE COURT: Yes.
    MR. KING: There's never been an allegation that Ms. DeSaveur did
    anything wrong in this case, and there's never been a disclosure in any
    pleading that there was a failure to supervise in this case. It came up on the
    fly in his deposition in mid November of this year.
    So we object on that basis. It's not a pleaded theory of recovery.
    THE COURT: Well, my understanding is this came out of Mr.
    Sweetser's opening statements, also.
    MR. KING: That doesn't-
    THE COURT: Yeah, but you didn't object. I assumed that was part
    of the theory of the case, so.
    MR. KING: Opening statement isn't evidence, and opening
    statement isn't a pleading. So I want to preserve my record, and I think that
    he's going into an area that it is impermissible for those reasons.
    THE COURT: I'll note your objection for the record.
    (BENCH CONFERENCE CONCLUDED.)
    THE COURT: You may proceed.
    Q (By Mr. Casey) Did you follow my question? Can you still
    answer it, Doctor?
    A I can't remember what it was.
    Q Do you have an opinion as to whether or not the x-ray of May
    27th from an orthopedic standpoint as to whether or not there was a
    violation of the standard of care in interpreting that x-ray?
    A I do.
    Q What is your opinion?
    A My opinion is that the May 27, 2009 x-ray was negligently
    interpreted. The fracture was misdiagnosed, and the orthopedic surgeon
    himself never actually saw that film at that time, which was a breach in the
    standard of care.
    Q And what information did you see that may lead someone to a
    sprained ankle in that diagnosis?
    A Nothing.
    14
    No. 32381-1-111
    Driggs v. Howlett, MD.
    Q Okay. You have an opinion as to whether that diagnosis violated
    the standard of care?
    MR. KING: Your Honor, again, same objection. Now we've
    changed from orthopedics to PA, which is a distinctly different issue.
    THE COURT: I'll sustain it at that point.
    Q (By Mr. Casey) Okay. Well, from the standpoint of should that
    have been delegated to a PA by an orthopedic surgeon as far as the
    management of Mr. Driggs considering his surgery?
    A No.
    Q And if an orthopedic surgeon had considered it, what would the
    standard of care require?
    A If an orthopedic surgeon had considered the symptoms, the
    presentation and the x-ray, the standard of care would have required the
    diagnosis to be that of a fracture through the screw hole post-operatively.
    3 VRP (Jan. 9, 2014) at 399-402, 405.
    On January 13, 2014, the trial court entertained additional argument on Providence
    Physician Services' motion to exclude portions of Dr. Lawrence Menendez's testimony.
    Providence contended that Dr. Menendez must know the Washington standard of care
    and may not rely on other experts to establish the foundation for his testimony. Also,
    Providence argued that all of Dr. Menendez's opinions were personal opinions and did
    not meet the testimonial requirement that a medical expert's testimony be based on a
    degree of reasonable medical probability. Providence also asked to exclude Dr.
    Menendez's testimony on whether removing the plate without installing a rod was a
    material risk and required Joshua Driggs' informed consent. Providence argued that Dr.
    Menendez never provided any testimony as to the scientific nature of the risk and the
    likelihood of its occurrence.
    15
    No. 32381-1-III
    Driggs v. Howlett, MD.
    The trial court granted Providence's motion to exclude Dr. Menendez's testimony
    about the standard of care, medical causation, and risk for informed consent. The court
    observed that no law supported Joshua Driggs' reliance on another physician's testimony
    to lay the foundation for Dr. Lawrence Menendez's opinion that the Washington and
    national standards of care correspond. In its ruling, the trial court noted that Lawrence
    Menendez never agreed, in response to counsel's direction, to base his opinion on
    reasonable medical probability. The trial court also noted that Dr. Menendez, in response
    to questioning by defense counsel, commented that his opinions are personal opinions.
    Providence Physician Services called to testify Orthopedic Surgeon James
    Bruckner, of Bellevue, Washington. Despite Dr. Steven Graboff earlier claiming to the
    contrary, Dr. Bruckner, at trial, denied testifying in his deposition that the national and
    Washington standards of care corresponded. Bruckner testified at trial that he had no
    knowledge of whether the state of Washington standard equated with the national
    standard. Dr. Bruckner testified that, under the standard applied in Washington, if not
    nationally, an orthopedist exercises discretion as to whether or not fixation is needed for
    the allograft. In other words, fixation is not always demanded. Dr. Bruckner conceded,
    nonetheless, that he has never removed fixation for an allograft without substituting other
    fixation.
    On January 15, 2014, Joshua Driggs submitted additional and alternative jury
    instructions and a proposed jury verdict form that allowed the jury to find Providence
    16
    No. 32381-1-111
    Driggs v. Howlett, MD.
    Physician Services liable if the jury found negligence by Dr. Andrew Howlett or
    Physician Assistant Brandi DeSaveur. On January 17, 2014, Driggs requested the trial
    court to reverse its decision to exclude Dr. Menendez's testimony. Driggs
    contemporaneously submitted supplemental declarations of Dr. Menendez stating the
    standard of care in Washington is equivalent to the national standard of care and that he
    based his testimony on a more probable than not basis to a reasonable degree of medical
    certainty. The trial court refused to reverse its ruling.
    On January 23, 2014, the trial court hosted exceptions and objections to the
    proposed jury instructions. Providence Physician Services objected to Joshua Driggs'
    proposed jury instruction thirteen, which allowed the jury to find Providence liable if it
    found Brandi DeSaveur, as an agent of Providence, negligent. In tum, Driggs argued:
    You don't have to name a specific agent when you sue a corporation, and
    our theory of the case is the corporation is negligent. Dr. Howlett is negligent.
    PAC Brandy [sic] Desaveur is negligent, and Janette Worley are negligent, and
    they're agents of the corporation, and we've proven that they're agents and acting
    within th~ scope of their employment.
    10 VRP (Jan. 23, 2014) at 1597.
    The trial court rejected Joshua Driggs' instruction thirteen and approved a jury
    verdict form that identified only Dr. Andrew Howlett as an agent of Providence. During
    argument on the instruction, the trial court stated:
    So you can argue Brandy [sic] DeSaveur and Janette Worley, but to put
    them in the instruction, this is the law. The law is that you are accusing Dr.
    Howlett of not supervising. Therefore, Brandy DeSaveur and Janette Worley
    17
    Ii
    No. 32381-1-111
    Driggs v. Howlett, MD.
    should [sic] be on the instruction, but you can argue it because that's your theory
    of the ace [sic].
    So I am going to let him argue that depending on how the argument comes,
    but the theory of the case is that Dr. Howlett was negligent by not reviewing it.
    Brandy [sic] DeSaveur didn't bring it to his attention according to Dr. Howlett's
    own testimony, and that in retrospect, he sees she missed.
    Depending on how you tie it in, Ms. DeSaveur is not being sued herself.
    She isn't listed in the Complaint, but the original was that she failed to bring it to
    his attention, and he should have supervised it and checked it. So it ties Dr.
    Howlett and Providence together.
    For the record, on the instructions, I will take off Brandy [sic] DeSaveur
    and Janette Worley and just leave Dr. Howlett.
    10 VRP (Jan. 23, 2014) at 1598-99, 1604.
    During closing arguments, Providence Physician Services focused on the dearth of
    reliable expert testimony supporting Joshua Driggs' case. Providence attacked the
    credibility of Dr. Steven Grabo ff and emphasized the lack of opinions from Dr. Lawrence
    Menendez on the standard of care, causation, and risks:
    So Mr. Casey [Joshua Driggs' counsel] wanted to talk to you about
    circumstantial evidence, and that's fine. That's totally appropriate. Does
    anybody remember Dr. Graboff? Mr. Casey must not because he spent an
    hour talking to you of their only witness on the standard of care in this case
    and didn't mention his name, didn't mention his name. You spent a day of
    your life listening to this expert on the standard of care, and apparently, Mr.
    Casey is so concerned that someone may discuss what Dr. Grabo ff says that
    he hopes it doesn't come to your attention and nobody will talk about him.
    This entire case on the standard of care theory rests on the very
    slender and very fragile and very unstable threat of the testimony of one
    physician, Dr. Graboff. I just want to talk for a minute about the plaintiffs
    case.
    The plaintiffs claim here there was a violation of the standard of care
    by Dr. Howlett in connection with this surgery. The reason that you're
    going to be asked to adjudicate that claim of the two claims that have been
    18
    I
    I
    No. 32381-1-III
    Driggs v. Howlett, MD.
    filed here is because they brought in an expert, Dr. Graboff, who said that
    it's a violation of the standard of care not to put fixation in after the
    hardware was removed from the allograft in this case. That was his
    testimony, okay?                               .
    The other expert they brought in who was mentioned twice in Mr.
    Casey's closing argument and only after 40 minutes of talking about what
    he says is circumstantial evidence, is Dr. Menendez. Let's just imagine that
    the only case you had to adjudicate here was the standard of care case and
    the only witnesses you heard from were Dr. Graboff and Dr. Menendez
    because those are the two experts that the plaintiff called to prove that my
    client violated the standard of care. Put yourself in that position.
    What do we know about how to evaluate that testimony? Well, the
    Judge just told you in the instructions what you can do to evaluate
    credibility, to evaluate bias, to evaluate whether or not they have adequate
    training and credentials. Let's stack up plaintiffs two experts against each
    other.
    Dr. Graboffhasn't done surgery since 2005, was kicked out of the
    most prestigious organization for orthopedic surgeons in the country
    because he violated their ethical codes having to do with testimony.
    He makes in excess of $400,000 a year traveling around the country
    testifying against other physicians in medical malpractice litigation. He has
    not had hospital privileges since 2005. He has testified in more than 160
    cases against healthcare providers on behalf of plaintiffs. He's given more
    than 500 depositions in medical-related claims and cases all on the side of
    or substantially on the side of the plaintiff.
    He's a hired gun. Is he well trained? We know his struggles to get
    into medical school to begin with. He applied to 16 schools throughout the
    country, was rejected by every one of them. He went to medical school in
    Mexico for four years, and at the end of each year, applied to a medical
    school in the United States and was turned down. Finally was admitted to
    UC Irvine, finished his medical school, got into a decent residency program
    at UCLA, got his credentials as an orthopedic surgeon in 1984 and quit
    doing surgery in 2005. Then he tried to recertify as an orthopedic surgeon,
    pass his boards again and he flunked twice.
    He is not Fellowship trained. He's never authored a single article in
    the peer-reviewed medical literature. He is for hire. That's what the
    evidence shows in this case. That's their expert. That's Dr. Graboff.
    Who is their other expert? Dr. Menendez. Well-qualified
    individual, Fellowship trained orthopedic oncologist, teaches at an
    19
    No. 32381-1-111
    Driggs v. Howlett, MD.
    academic center. Remember the Musculoskeletal Tumor Society, the
    organization that kicked Dr. Dr. [sic] Graboff off?
    He testified by videotape. Did he say that Dr. Howlett violated the
    standard of care any way, shape or form in this case? No. Did he say that
    fixation hardware if put in place in March of '09 would have prevented this
    fracture? No. Did he provide any information to you that there was a
    violation of the standard of care in the postoperative management of this
    patient after the March 6, 2009 surgery by Dr. Howlett? No.
    Did he say there was a violation of the standard of care having to do
    with the interpretation of the May 27, 2009 x-ray? No.
    Did he say that but for the failure to put in fixation hardware in this
    case, Mr. Driggs with his ankle fusion and his previously failed allograft
    would have no difficulty or problem with his lower extremity? No.
    That's the plaintiffs case on the standard of care. That's the quality
    of the evidence that they put on, and the quality of the evidence that they
    put on as it relates to their standard of care claim rests entirely on an expert.
    who will, I think you could find, go anywhere at any time and say anything
    to support a claim against a physician and has done it and apparently has no
    compunction about continuing to do it. That's their case on standard of
    care in their own case.
    10 VRP (Jan. 23, 2014) at 1687-91.
    The jury entered a verdict in favor of Providence Physician Services.
    LAW AND ANALYSIS
    On appeal, Joshua Driggs contends that the trial court abused its discretion by
    excluding expert testimony of Dr. Lawrence Menendez. He also maintains that the trial
    court erred in refusing its proposed jury instruction naming Brandi DeSaveur as an
    employee accused of negligence. Driggs claims either error by itself constituted harm
    that requires remand for a new trial. We focus on the exclusion of Lawrence Menendez's
    testimony and opinions.
    f
    20                                           II
    f
    l
    No. 32381-1-111
    Driggs v. Howlett, MD.
    Lawrence Menendez's Testimony
    The trial court excluded Dr. Lawrence Menendez's opinions regarding the
    standard of care for fixation of allografts, the absence of fixation causing a fracture and
    other complications in Joshua Driggs's right leg, and the risks attended to the absence of
    fixation. The trial court excluded testimony on the standard of care because Dr.
    Menendez did not testify to a Washington standard of care. The court barred testimony
    on causation because Menendez never stated that he based his opinion on reasonable
    medical probability. The trial court rejected testimony on the risk for purposes of
    informed consent because Menendez did not reference percentages of the risk. In its
    ruling, the trial court also mentioned that Menendez agreed with defense counsel that his
    opinions were personal opinions. An expert's testimony as to his personal opinions could
    be a basis to reject all opinions stated, although the record does not show which of the
    opinions the trial court excluded on this basis.
    We review the decision to exclude an expert witness's testimony for abuse of
    discretion. Winkler v. Giddings, 
    146 Wash. App. 387
    , 392, 
    190 P.3d 117
    (2008).
    Discretion is abused if it is exercised on untenable grounds or for untenable reasons.
    Morin v. Burris, 
    160 Wash. 2d 745
    , 753, 
    161 P.3d 956
    (2007). Important for this appeal is
    the rule that a decision is based on untenable grounds or made for untenable reasons if it
    was reached by applying the wrong legal standard. Mitchell v. Wash. State Inst. ofPub.
    Policy, 
    153 Wash. App. 803
    , 821-22, 
    225 P.3d 280
    (2009). A trial court that
    t
    21
    I
    t
    No. 32381-1-111
    Driggs v. Howlett, MD.
    misunderstands or misapplies the law bases its decision on untenable grounds. Little v.
    King, 
    160 Wash. 2d 696
    , 703, 
    161 P.3d 345
    (2007). In reviewing a ruling for abuse of
    discretion, this court will often separate questions of fact from the conclusions of law that
    they support and refuse to defer to the trial court on conclusions of law. Bartlett v.
    Betlach, 
    136 Wash. App. 8
    , 18, 
    146 P.3d 1235
    (2006).
    State Standard of Care
    As a preliminary matter, the parties dispute whether the trial court correctly
    disallowed a supplemental declaration from Dr. Lawrence Menendez. Joshua Driggs
    filed the declaration after the perpetuation deposition of Dr. Menendez and in response to
    Providence Physician Services' motion to strike testimony of Menendez. In the
    declaration, Dr. Menendez disclosed that he conferred with experts within Washington
    State and determined that the Washington standard of care was equivalent to the national
    standard concerning the need for fixation of an allograft. We decline to resolve whether
    the trial court abused its discretion when refusing to consider this additional testimony of
    Menendez. Even without the declaration testimony, we rule that Dr. Menendez's opinion
    on the standard of care should have been heard by the jury. Principles of judicial restraint
    dictate that if resolution of another issue effectively disposes of a case, we should resolve
    the case on that basis without reaching the first issue presented. Wash. State Farm
    Bureau Fed'n v. Gregoire, 
    162 Wash. 2d 284
    , 307, 
    174 P.3d 1142
    (2007); Hayden v. Mut.
    of Enumclaw Ins. Co., 
    141 Wash. 2d 55
    , 68, 
    1 P.3d 1167
    (2000).
    22
    No. 32381-1-111
    Driggs v. Howlett, MD.
    In a medical malpractice claim, a plaintiff must show that the health care provider
    violated the relevant standard of care. A plaintiff must prove the relevant standard of
    care through the presentation of expert testimony, unless a limited exception applies.
    Volk v. Demeerleer, 
    184 Wash. App. 389
    , 430-31, 33·7 P.3d 372 (2014), review granted,
    
    183 Wash. 2d 1007
    (2015). In tum, the trial judge must make a preliminary finding of fact
    under ER 104(a) as to whether an expert is qualified to express an opinion on the
    standard of care in Washington. Winkler v. 
    Giddings, 146 Wash. App. at 392
    (2008).
    By Washington statute, the standard of care is the degree of "care, skill, and
    learning expected of a reasonably prudent health care provider at that time in the
    profession or class to which he belongs, in the state of Washington, acting in the same or
    similar circumstances." RCW 7.70.040 (emphasis added). One might question if the
    standard of care in Washington ever differs from the standard of care throughout the
    nation. Law changes from state to state, but medical care holds constant throughout
    America, at least outside rural areas. Increasingly, medical experts testify that
    Washington follows a national standard of care. We remain bound, however, by our
    legislature's declaration that the trier of fact must find and apply a state standard of care.
    Joshua Driggs suggests that a trier of fact may assume that the national standard of
    care and the state standard of care coalesce unless one witness testifies to a differing
    standard. A lax reading of Winkler v. Giddings, 
    146 Wash. App. 387
    (2008) and Pon
    Kwack Eng v. Klein, 
    127 Wash. App. 171
    , 
    110 P.3d 844
    (2005) could support such a rule.
    23
    No. 32381-1-111
    Driggs v. Howlett, MD.
    In each decision, this court underlined the absence of testimony from the defending
    physician that Washington retained a variant standard of care. Nevertheless, neither case
    expressly adopted such a rule. We need not decide whether to adopt such a rule because
    we may rest our decision on other grounds.
    A physician licensed in another state may provide admissible testimony that a
    national standard of care exists in this state and that the defendant physician violated that
    standard. Elber v. Larson, 
    142 Wash. App. 243
    , 248, 
    173 P.3d 990
    (2007); Pon Kwock Eng
    v. 
    Klein, 127 Wash. App. at 179
    . In his deposition, Dr. Lawrence Menendez testified that
    Dr. Andrew Howlett violated the national standard of care of an orthopedist oncologist by
    failing to affix the allograft during the March 6, 2009 surgery. Menendez did not affirm
    that the Washington standard of care followed the national standard of care.
    Nevertheless, Dr. Steven Graboff at trial averred that the national and Washington
    standards of care are equivalent. We rule that Dr. Graboffs testimony lays a sufficient
    predicate for Dr. Menendez's opinion.
    Providence Physician Services contends that the only type of expert competent to
    testify as to the standard of care required of a practitioner in the state of Washington is an
    expert who knows the practice and standard of care in Washington. Providence cites
    McKee v. American Home Products Corporation, 
    113 Wash. 2d 701
    , 706-07, 782 P .2d 1045
    (1989) for this proposition. McKee included a claim of pharmacist malpractice. The only
    evidence provided by the plaintiff concerning the standard of care of a pharmacist
    24
    No. 32381-1-111
    Driggs v. Howlett, MD.
    practicing in Washington was an affidavit of an Arizona physician. The Supreme Court
    disregarded the opinion of the physician because he was not a pharmacist. The Supreme
    Court also rejected the opinion because the physician did not reference the standard of
    care of a pharmacist in this state. McKee v. American Home Products Corporation does
    not address our issue: whether one physician may testify solely to a national standard of
    care when another physician testifies that the Washington standard echoes the national
    standard.                                                                                     i
    I
    II
    Providence Physician Services argues that allowing a witness's familiarity with
    the applicable standard of care to be established through other witnesses would subvert
    the process of expert witness qualification. In other words, Providence advocates a rule
    that would require that an expert in a medical malpractice case know the standard of care
    in Washington State before the trial court accepts the witness as an expert. In so arguing,
    Providence may confusingly conflate the qualifications of an expert witness to testify
    with the opinions to which the witness may testify. No rule requires that an expert
    possess, within his personal knowledge, all information necessary to qualify him as an
    expert witness. No rule precludes a party from relying on one expert witness for a
    portion of needed evidence and another expert witness for another segment of required
    testimony. RCW 7.70.040 does not preclude a party from relying on more than one
    medical expert to establish that the defendant health care provider violated the standard
    of care in Washington. Thus, based on Washington case law discussed below, we hold
    25
    No. 32381-1-III
    Driggs v. Howlett, MD.
    that a qualified medical expert may testify to a national standard of care alone if another
    qualified medical expert at the same trial testifies that the Washington standard parallels
    the national standard.
    One expert may rely on the opinions of another expert when formulating opinions.
    State v. Russell, 
    125 Wash. 2d 24
    , 69, 
    882 P.2d 747
    (1994); Volk v. Demeerleer, 184 Wn.
    App. at 430-31 (2014); Deep Water Brewing, LLC v. Fairway Res. Ltd., 
    152 Wash. App. 229
    , 271, 
    215 P.3d 990
    (2009). This rule may assume that the testifying expert has
    contacted another expert and gained information from the second expert before testifying.
    Dr. Menendez did not learn, before his perpetuation deposition, from another physician
    that the national standard of care and state standard coincided. We see no difference
    however, for practical purposes, if the litigant, rather than the expert witness, presents
    such information at trial through the second expert. In other words, we conclude the
    plaintiff may call to the stand the second expert to notify the jury that the state standard
    echoes the national standard particularly when the first expert could have called the
    second expert on the phone to learn of the state standard and repeat the second expert's
    comments to the jury. If anything, the evidence for the plaintiff strengthens if the second
    witness provides the foundation during trial testimony, since the jury hears the additional
    information directly from the second expert rather than through the first witness's hearsay
    statement of what another expert told him. The second expert's opinion that the
    Washington standard equates to the United States standard also then become subject to
    26
    No. 32381-1-111
    Driggs v. Howlett, MD.
    cross-examination by the defense. Joshua Driggs' jury heard first hand from Dr. Steven
    Graboffthat the national standard of care and state standard of care conflate. Driggs
    accomplished directly what he could have achieved indirectly through an earlier phone
    conversation between Dr. Lawrence Menendez and Dr. Steven Graboff. Thus, Lawrence
    Menendez's testimony as to the national standard was admissible.
    Three decisions, Hill v. Sacred Heart Medical Center, 
    143 Wash. App. 438
    , 177
    PJd 1152 (2008), Winkler v. Giddings, 
    146 Wash. App. 387
    (2008), and Elber v. Larson,
    
    142 Wash. App. 243
    (2007) discuss to varying extents the issue presented in this appeal.
    Providence Physician Services relies on Winkler v. Giddings. In Winkler, plaintiffs
    expert testified to an "educated assumption that the standard of care was the same across
    the 
    country." 146 Wash. App. at 392
    . Plaintiff presented no other evidence that the
    Washington standard of care followed the national standard. Dr. Neil Giddings presented
    testimony that the relevant standard of care differed depending on the area of the country.
    Winkler is easily distinguishable because Joshua Driggs presented the additional
    testimony from Steven Graboff. Dr. Andrew Howlett presented no testimony of a
    varying standard of care from one region to another.
    In Elber v. Larson, the physician in a medical malpractice suit moved for
    summary judgment. The physician contended that plaintiffs witness, Dr. Daniel Meub,
    was not qualified as an expert witness because Meub lacked background, training or
    experience in Washington. The trial court granted summary judgment. This court
    27
    No. 32381-1-III
    Driggs v. Howlett, MD.
    reversed and held that a medical expert is qualified to testify to the Washington standard
    of care if he offers uncontradicted testimony that he is familiar with the standard of care
    and that the standard is a national standard.
    A compelling decision is Hill v. Sacred Heart Medical Center. Plaintiff John Hill
    presented testimony from two physicians. One physician testified that the national
    standard of care controlled the conduct of the defendants, but did not expressly state that
    he knew the Washington standard of care to coincide with the national standard. A
    second physician testified that she knew the Washington standard to parallel the national
    standard. This court relied on both physicians' testimony when reversing a summary
    judgment dismissal of the medical malpractice suit.
    We recognize that Joshua Driggs presented at trial the deposition of Dr. Lawrence
    Menendez before presenting Dr. Steven Graboffto testify. Nevertheless, an evidence
    rule allows testimony to be presented at trial when that testimony is admissible only on
    the assumption that later testimony is presented. ER 104(b).
    We recognize the need to defer to the trial court in evidentiary rulings.
    Nevertheless, the trial court's exclusion of Dr. Lawrence Menendez's testimony resulted
    from a misapplication of the law. Thus, we rule the trial court abused its discretion.
    Providence Physician Services distinguishes Elber v. Larson and Hill v. Sacred
    Heart Medical Center on the grm,md that the trial court disregarded expert opinions when
    II
    addressing a summary judgment motion and this court reviews evidentiary rulings de            I
    28
    No. 32381-1-III
    Driggs v. Howlett, MD.
    novo when examining a summary judgment ruling. We recognize this distinction, but we
    may still reverse a trial court evidentiary ruling at trial based on a misperception of the
    law.
    Reasonable Medical Probability
    Joshua Driggs next challenges the trial court's decision to exclude Dr. Lawrence
    Menendez's testimony on medical causation. Dr. Menendez opined that removing a plate
    from a grafted cadaver bone without replacing the plate with another plate or rod likely
    leads to a fracture. Thus, according to Menendez, the failure by Dr. Andrew Howlett to
    insert a rod caused Joshua Driggs' tibia to fracture and led to other complications.
    Providence Physician Services argues that Dr. Menendez's testimony is incompetent
    because he failed to affirmatively testify that his testimony was based on a reasonable
    degree of medical probability. Driggs argues that Menendez expressed an opinion on
    causation based on reasonable medical probability, even if Menendez did not expressly
    acknowledge in his deposition that his testimony would do so. We concur with Joshua
    Driggs.
    We repeat the relevant passage in Dr. Lawrence Menendez's perpetuation
    deposition:
    Q And, Doctor, again, I want you to base your opinions on
    reasonable degree of medical certainty based upon what's more likely than
    not likely as I ask you questions about your opinions in this regard.
    Did you have a chance to look at X-rays after the surgery in March
    of2009?
    29
    No. 32381-1-111
    Driggs v. Howlett, MD.
    A Yes.
    Q Doctor, do you have an opinion, based upon what's more
    probable than not-more likely than not as to whether or not had there been
    a rod placed, it would not have fractured when it did?
    MR. KING: Same objection.
    Go ahead, Doctor.
    THE WITNESS: So if you put internal fixation in in a form of a
    rod, there's a likelihood that the allograft will fracture.
    So it's less likely that you'll get a fracture if you put fixation in to
    support the allograft. If you don't put fixation in, it's more likely that
    you'll have a fracture for the reasons I discussed earlier.
    CP at 1347, 1350-51.
    Note that Dr. Menendez did not respond, let alone affirmatively respond, to Joshua
    Driggs' counsel's instruction to base his opinions on a reasonable degree of medical
    certainty. Nevertheless, as to Menendez's opinion on causation, Menendez responded to
    a question as to whether he held an opinion based on what's more probable than not.
    Litigation counsel would be wise to insist that a medical expert agree to expressly affirm
    that his opinions will be based on reasonable medical probability, before counsel asks
    questions. In the alternative, litigation counsel would be wise to phrase ever critical
    questions in terms of reasonable medical probability based on the expert's experience and
    training. Nevertheless, we agree with Joshua Driggs that, reviewing the deposition as a
    whole, Menendez formulated his opinion on causation based on reasonable medical
    probability.
    Generally, expert medical testimony on the issue of proximate cause is required in
    30
    No. 32381-1-111
    Driggs v. Howlett, MD.
    medical malpractice cases. McLaughlin v. Cooke, 
    112 Wash. 2d 829
    , 837-38, 
    774 P.2d 1171
    ( 1989); Hill v. Sacred Heart Med. 
    Ctr., 143 Wash. App. at 448
    (2008). Evidence
    establishing proximate cause in medical malpractice cases must rise above speculation,
    conjecture, or mere possibility. Reese v. Stroh, 
    128 Wash. 2d 300
    , 309, 
    907 P.2d 282
                                                                                                 I
    (1995). Instead, medical expert testimony must be based on a "reasonable degree of
    medical certainty." Reese v. 
    Stroh, 128 Wash. 2d at 305-06
    . Despite the use of the term
    "certainty" in some opinions, "probability" is sufficient. Reasonable medical probability
    and reasonable medical certainty are used interchangeably. Anderson v. Akzo Nobel
    Coatings, Inc., 
    172 Wash. 2d 593
    , 607, 
    260 P.3d 857
    (2011).
    Whereas the plaintiff must present testimony that the defending health care
    provider's breach of the standard of care resulted in injury, the law does not require the
    uttering of any talismanic words. We do not require experts to testify in a particular
    format but instead look at the substance of the allegations and the substance of what the
    expert brings to the discussion. Leaverton v. Cascade Surgical Partners, PLLC, 160 Wn.
    App. 512, 520, 
    248 P.3d 136
    (2011). To require experts to testify in a particular format
    would elevate form over substance. White v. Kent Med. Ctr. Inc., 
    61 Wash. App. 163
    , 172,
    
    810 P.2d 4
    (1991).
    In excluding the testimony, the trial court relied on the absence of Dr. Lawrence
    Menendez's affirmative reply that he would ground his opinion on a reasonable degree of
    medical certainty. Nevertheless, when asked the key question with regard to causation,
    31
    I
    No. 32381-1-III
    Driggs v. Howlett, MD.
    Dr. Menendez provided an opinion based on probability. When questioned by
    Providence Physician Services, Dr. Menendez affirmed that he grounded his opinions on
    his medical expertise, education, and experience. The beginnings of Dr. Menendez's
    deposition established him as a premier expert on orthopedic oncology and allografts.
    From the sum of the testimony, one must conclude that Dr. Menendez's testimony of
    causation was based on reasonable medical probability. Conversely, Dr. Menendez
    rendered no speculative or conjectural opinions.
    White v. Kent Medical Center Inc., 
    61 Wash. App. 163
    (1991) is illustrative. Two
    doctors testified that a vocal cord examination is required for a patient with a four to six
    week history of hoarseness. Neither physician expressly testified that the defendant
    physician violated the standard of care by failing to perform the examination. This court
    ruled that the two doctors' testimony sufficed to defeat a summary judgment motion in
    the medical malpractice suit. "Standard of care" language was not essential to the
    admissibility of the opinions. At issue in this appeal is whether the expert testified to
    reasonable medical probability not the standard of care. Nevertheless, the same principle
    of promoting substance over form controls our decision.
    Materiality ofRisk
    In addition to asserting a cause of action for professional negligence, Joshua
    Driggs alleges that Dr. Andrew Howlett failed to obtain his informed consent to the            I
    March 9, 2009 surgery. Driggs argues that Dr. Howlett should have warned him of the
    , 32
    No. 32381-1-111
    Driggs v. Howlett, MD.
    risks of leaving the allograft without hardware fixation. Howlett contends he warned
    Driggs of the risks, so the jury needed to decide who told the truth. To bolster his claim
    of informed consent, Joshua Driggs sought to introduce testimony of Dr. Lawrence
    Menendez about the risks of omitting any fixation. The trial court disallowed the
    testimony on the ground that Dr. Menendez did not testify to any percentage of the risk
    and provided no statistics regarding fractures resulting from the absence of fixation. The
    trial court nonetheless, presumably based on testimony of Dr. Steven Graboff, allowed
    the jury to render a verdict on the informed consent claim. Driggs assigns error to the
    exclusion ofMenendez's testimony.
    Dr. Lawrence Menendez testified little about the risk from no fixation for the
    allograft and the little testimony may have been targeted more to the claim of medical
    malpractice than the lack of informed consent. Lawrence Menendez testified that, when
    removing hardware from an allograft, the surgeon wants to insert new hardware to
    minimize the risk of fracture. He further testified that "it is less likely" that the bone will
    fracture if the surgeon inserts fixation. Conversely, omitting fixation renders the bone
    "more likely" to fracture. We must decide whether this medical testimony is admissible
    for determining the materiality of a risk for an informed consent cause of action.
    The doctrine of informed consent refers to the requirement that a physician, before
    obtaining the consent of his or her patient to treatment, inform the patient of the
    treatment's attendant risks. Smith v. Shannon, 
    100 Wash. 2d 26
    , 29, 
    666 P.2d 351
    (1983).
    33
    No. 32381-1-111
    Driggs v. Howlett, MD.
    The doctrine is premised on the fundamental principle that every human being of adult
    years and sound mind has a right to determine what shall be done with his own body.
    Smith v. 
    Shannon, 100 Wash. 2d at 29
    . A necessary corollary to this principle is that the
    individual be given sufficient information to make an intelligent decision. Smith v.
    
    Shannon, 100 Wash. 2d at 29
    .
    RCW 7.70.050 codifies the elements of a cause of action for informed consent.
    The statute defines a "material fact" as one to which
    a reasonably prudent person in the position of the patient or his or
    her representative would attach significance [in] deciding whether or not to
    submit to the proposed treatment.
    RCW 7.70.050(2). "Material facts" include:
    (a) The nature and character of the treatment proposed and
    administered;
    (b) The anticipated results of the treatment proposed and
    administered;
    (c) The recognized possible alternative forms of treatment; or
    (d) The recognized serious possible risks, complications, and
    anticipated benefits involved in the treatment administered and in the
    recognized possible alternative forms of treatment, including nontreatment.
    RCW 7.70.050(3).
    Case law adds flesh to the cause of action for informed consent. Under the
    doctrine of informed consent, a health care provider has a fiduciary duty to disclose
    relevant facts about the patient's condition and the proposed course of treatment so that
    the patient may exercise the right to make an informed health care decision. Stewart-
    34
    No. 32381-1-111
    Driggs v. Howlett, MD.
    Gravesv. Vaughn, 
    162 Wash. 2d 115
    , 122, 170P.3d 1151 (2007);Millerv. Kennedy, 
    11 Wash. App. 272
    , 282-83, 
    522 P.2d 852
    (1974), aff'd, 
    85 Wash. 2d 151
    , 
    530 P.2d 334
    (1975).
    Nevertheless, a physician need not disclose every risk that could be disclosed, if only
    because of the time required to disclose every remote risk. Smith v. 
    Shannon, 100 Wash. 2d at 30
    (1983); Ruffer v. St. Frances Cabrini Hosp. ofSeattle, 
    56 Wash. App. 625
    , 632, 
    784 P.2d 1288
    (1990). A physician only has a duty to disclose material risks. RCW
    7.70.050; Smith v. 
    Shannon, 100 Wash. 2d at 31
    ; Seyboldv. N~u, 
    105 Wash. App. 666
    , 681,
    
    19 P.3d 1068
    (2001). The physician need only disclose risks of serious harm that are
    reasonably foreseeable. Smith v. 
    Shannon, 100 Wash. 2d at 31
    . The duty to disclose
    similarly attaches to recognized possible alternative forms of treatment and to the
    anticipated results of the treatment proposed and administered. Adams v. Richland
    Clinic, Inc., 
    37 Wash. App. 650
    , 657, 
    681 P.2d 1305
    (1984).
    Parallel to the requirement of expert testimony in a medical malpractice suit, an
    informed consent action usually demands medical expert testimony. In an informed
    consent action, the patient must present expert testimony to prove the existence of a risk,
    its likelihood of occurrence, and the type of harm in question. Smith v. 
    Shannon, 100 Wash. 2d at 34
    . To determine whether such a risk is material, courts engage in a two-step
    analysis. First, the scientific nature of the risk must be ascertained, i.e., the nature of the
    harm that may result and the probability of its occurrence. Smith v. 
    Shannon, 100 Wash. 2d at 33
    . Second, the trier of fact must decide whether the probability of that type of harm is
    35
    No. 32381-1-III
    Driggs v. Howlett, MD.
    a risk which a reasonable patient would consider in deciding on treatment. Smith v.
    
    Shannon, 100 Wash. 2d at 33
    .
    Expert testimony is needed only for the first step of the informed consent two-step
    analysis. Smith v. 
    Shannon, 100 Wash. 2d at 33
    . The second step of this determination of
    materiality does not require expert testimony. Smith v. 
    Shannon, 100 Wash. 2d at 33
    . A
    jury armed with information as to the nature and materiality of the risk may determine
    whether a reasonable patient would desire such information. The jury, as laymen and
    laywomen, are equipped to place themselves in the position of a patient and decide
    whether, under the circumstances, the patient should have been told. Smith v. 
    Shannon, 100 Wash. 2d at 32
    ; Miller v. 
    Kennedy, 11 Wash. App. at 288-89
    (1974); Keogan v. Holy
    Family Hosp., 
    95 Wash. 2d 306
    , 318, 
    622 P.2d 1246
    (1980).
    The trial court did not identify the rule of evidence employed to exclude Dr.
    Lawrence Menendez's testimony on informed consent. Instead, the trial court noted that
    Lawrence Menendez failed to assign a percentage to the risk of a fracture with the
    absence of fixation. We assume the trial court deemed Menendez's testimony about the
    likelihood of a fracture to be irrelevant to an informed consent cause of action. In tum,
    we presume that the court concluded that Menendez's testimony provided no assistance
    to the jury.
    ER 702 governs competency of expert testimony. The rule reads:
    If scientific, technical, or other specialized knowledge will assist the
    36
    No. 32381-1-III
    Driggs v. Howlett, MD.
    trier of fact to understand the evidence or to determine a fact in issue, a
    witness qualified as an expert by knowledge, skill, experience, training, or
    education, may testify thereto in the fonn of an opinion or otherwise.
    Under ER 702, expert testimony is admissible if ( 1) the witness qualifies as an expert,
    and (2) the testimony is helpful to the trier of fact. State v. Cauthron, 
    120 Wash. 2d 879
    ,
    890, 
    846 P.2d 502
    (1993). Dr. Menendez's qualifications are not in dispute. Thus, the
    question we resolve is whether the trial court abused its discretion when it determined
    Menendez's testimony would not help the trier of fact.
    Expert testimony by a qualified expert is admissible if it is helpful to the trier of
    fact. State v. 
    Cauthron, 120 Wash. 2d at 890
    . Under ER 702, expert testimony will be
    deemed helpful to the trier of fact only if its relevance can be established. State v.
    Greene, 
    139 Wash. 2d 64
    , 73, 
    984 P.2d 1024
    (1999). Expert testimony assists a jury if the
    testimony concerns matters beyond the common knowledge of the average layperson and
    is not misleading. State v. Groth, 
    163 Wash. App. 548
    , 564, 
    261 P.3d 183
    (2011). Courts
    generally interpret possible helpfulness to the trier of fact broadly and will favor
    admissibility in doubtful cases. State v. 
    Groth, 163 Wash. App. at 564
    ; Moore v. Hagge,
    
    158 Wash. App. 137
    , 155, 
    241 P.3d 787
    (2010).
    We conclude that Dr. Lawrence Menendez's testimony, that the failure to replace
    the fixation would likely lead to a fracture, would help a jury in understanding the risk of
    Dr. Andrew Howlett's omission of fixation after the March 9, 2009 surgery. The risk
    attended to the lack of fixation for the allograft is not information known to the
    37
    No. 32381-1-111
    Driggs v. Howlett, MD.
    layperson. Providence Physician Services cites no case that holds a medical expert may
    not testify to a likelihood of a risk reaching fruition because the expert fails to assign a
    percentage to the risk. Nor do we find any Washington decision addressing this precise
    question.
    In another context, this court held that whether the expert provides statistical
    support for an opinion goes to the weight and not the admissibility of the testimony.
    Reese v. Stroh, 
    74 Wash. App. 550
    , 564, 
    874 P.2d 200
    (1994), aff'd on other grounds, 
    128 Wash. 2d 300
    , 
    907 P.2d 282
    (1995). In Reese, the defendant physician, in a medical
    malpractice action, sought to exclude testimony on causation from the patient's expert
    witness, under ER 702, on the ground that the expert failed to assign a percentage to the
    chance that the physician's negligence caused injury.
    A New Jersey intermediate appellate court, in Frost v. Brenner, 
    300 N.J. Super. 394
    , 
    693 A.2d 149
    (App. Div. 1997), addressed the question of whether a patient in an
    informed consent claim must present the statistical risk of a procedure. The appeals court
    reversed a trial court that dismissed the claim because the plaintiff failed to quantify the
    relevant risks. The New Jersey court reasoned that statistical evidence is not an
    indispensable requisite because the materiality of a risk is based on significance to the
    reasonable patient. 
    Frost, 300 N.J. Super. at 405
    . This ratiocination applies in
    Washington because the Washington standard for informed consent is likewise based on
    the significance of a risk to a reasonable patient, rather than from the physician's
    I
    Il
    38
    No. 32381-1-III
    Driggs v. Howlett, MD.
    standpoint. Smith v. 
    Shannon, 100 Wash. 2d at 32
    ; Miller v. 
    Kennedy, 11 Wash. App. at 288
    -
    89 (1974); Keogan v. Holy Family 
    Hosp., 95 Wash. 2d at 318
    (1980). If statistical evidence
    is not a prerequisite for an informed consent claim, a medical expert should be allowed to
    testify without mentioning percentages or statistics.
    Providence Physician Services faults Dr. Lawrence Menendez's testimony
    because Menendez declares that omitting fixation renders the bone "more likely" to
    fracture, but he does not contrast the possibility or probability of a fracture even with
    fixation. We consider this criticism to go to the weight ofMenendez's testimony, not its
    admissibility.
    Joshua Driggs argues that requiring statistical evidence would create an impossible
    task in his suit because none of the testifying physicians had omitted replacement
    hardware when removing hardware from an allograft. Since none of the witnesses
    omitted replacement fixation, none could testify to the percentage of cases when a lack of
    fixation resulted in a fracture. Of course, Driggs' argument fails to note that scores of
    physicians unrelated to this suit could have omitted replacement hardware and that
    literature might address the percentage of the risk. Nevertheless, since we rule in favor of
    Driggs on the issue on other grounds, we need not rely on this contention. We note,
    however, that Driggs' contention highlights a problem demanding statistical evidence
    when no reliable data exists to establish the risks of a medical procedure. Reliable data
    may regularly be absent in medical malpractice cases where a physician completely
    '
    39
    I
    f
    No. 32381-1-111
    Driggs v. Howlett, MD.
    deviated from common practices. Although informed consent requires physicians to
    inform patients of material risks before treatment, quantifying risks may require
    unreliable speculation when treatment is unique, even though the risks are material.
    Once again we recognize the trial court holds discretion in admitting and
    excluding evidence at trial. Nevertheless, the court abuses discretion when basing an
    evidentiary ruling on a misinterpretation of law. The law does not require an expert to
    assign a percentage to the risk of which the patient claims the physician did not inform
    him. Thus, the trial court erred in excluding Lawrence Menendez's opinion on the
    likelihood of the risk of omitting fixation.
    Personal Opinions
    The trial court mentioned that some or all of Dr. Lawrence Menendez's opinions
    were personal judgments. In its brief, Providence Physician Services does not seek to
    affirm the trial court's evidentiary rulings on the ground that Menendez expressed
    personal views. We deem ourselves compelled to address the issue, nonetheless, in order
    to assist on remand.
    Dr. Lawrence Menendez agreed, in cross-examination, that his opinions were his
    personal opinions. Providence Physician Services runs too far with the concession,
    however. The term "personal opinion" is fraught with ambiguity. Providence's position
    wrongly assumes that a professional opinion or an opinion shared widely by members of
    the medical community cannot also be the personal opinion of a medical expert witness.
    40
    No. 32381-1-111
    Driggs v. Howlett, MD.
    Some expert witnesses will not understand the distinction rendered by the law between a
    personal opinion and an admissible opinion based on the witness's experience, training,
    and research. An effective cross-examiner, such as Providence Physician Services'
    counsel, could obtain an indulgence from most, if not all, expert witnesses that opinions
    formulated based on their education, knowledge as a practitioner, and reading of
    literature constitute their personal opinions.
    An expert's personal opinion is insufficient to establish the recognized standard of
    care. White v. Kent Med. Ctr. 
    Inc., 61 Wash. App. at 172
    (1991). This principle must be
    read in context, however. Washington cases insinuate that an expert's personal opinion is
    admissible if the opinion is also a professional opinion. The test for admissibility is met
    so long as the court may conclude from the testimony that the expert discussed general,
    rather than personal, professional standards and expectations. Adams v. Richland 
    Clinic, 37 Wash. App. at 655-56
    (1991). In the context of standard of care testimony, this court
    has allowed an expert's opinion as long as the opinion is "more than a personal opinion."
    White v. Kent Med. 
    Ctr., 61 Wash. App. at 172
    . It is only necessary that an expert's
    opinion on the standard of care be based on general professional standards, rather than
    "mere" personal opinion. Leaverton v. Cascade Surgical Partners PLLC, 
    160 Wash. App. I
    at 520 (2011 ). Thus, a personal opinion may be impermissible only if idiosyncratic to the
    expert witness. A personal opinion may be inadmissible only if not shared by the
    expert's professional community.
    41
    II
    No. 32381-1-III
    Driggs v. Howlett, MD.
    Foreign cases refer to "subjective opinions" of the expert as being impermissible.
    Boyd v. State Farm Ins. Cos., 
    158 F.3d 326
    , 331 (5th Cir. 1998); Russell v. Call/D, LLC,
    
    122 A.3d 860
    , 867 (D.C. 2015); Padilla v. Loweree, 
    354 S.W.3d 856
    , 863 (Tex. App.
    2011 ). Otherwise, so long as a physician with a medical degree has sufficient expertise
    to demonstrate familiarity with the procedure or medical problem at issue, ordinarily he
    or she will be considered qualified to express an opinion on any sort of medical question.
    
    White, 61 Wash. App. at 173
    (quoting 5A KARLB. TEGLAND, WASHINGTON PRACTICE:
    EVIDENCE LAW AND PRACTICE§ 290(2), at 386 (3d ed. 1989)).
    Pop Kwock Eng v. Klein, 
    127 Wash. App. 171
    , 
    110 P.3d 844
    (2005) is illustrative.
    The plaintiff's expert physician testified:
    So my personal opinion would be that as a neurosurgeon, [Dr. Klein]
    should be very familiar with the signs and symptoms, diagnosis and
    treatment of meningitis. Now, that's not to say that he may not need to call
    in an expert to help him decide on exactly which antibiotics to choose and
    how long to treat them. That would be fine. But as far as recognizing the
    possibility of meningitis and knowing that a lumbar puncture is necessary
    to diagnose the meningitis, and to recognize that timely treatment is
    necessary in order to optimally improve the outcome of that patient, he
    should be aware of that, in my 
    opinion. 127 Wash. App. at 178-79
    (emphasis added). This court did not directly address the
    expert's couching his testimony in the words of a "personal opinion." We nonetheless
    accepted the testimony as admissible to show the professional standard of care to which
    the defendant physician was held.
    42
    No. 32381-1-111
    Driggs v. Howlett, MD.
    The record shows that opinions formulated by Dr. Lawrence Menendez were not
    "mere personal" or "subjective" opinions. Menendez is an experienced and noted
    orthopedic oncologist who presents papers at professional meetings. He was conversant
    with the national standard of care concerning fixation for allografts. In answer to
    questions on the standard of care, he spoke of his experience and presentations. He
    delivered articulate explanations for his opinions.
    Providence Physician Services also reads too much into Dr. Menendez's
    concession. When asked if the opinions expressed were his personal opinions, Menendez
    responded, "technically, I'm offering my opinion." CP at 1411. He added that he
    grounded his views on his "knowledge and expertise and education and experience." CP
    at 1411.
    A wealth of American case law supports a rule that only subjective or
    idiosyncratic personal opinions are impermissible and other personal opinions of an
    expert witness are admissible. Perhaps recognizing the ambiguity in the phrase "personal
    opinion," Texas law declares that an expert witness, as opposed to a lay or fact witness,
    may render a personal opinion. United Way ofSan Antonio, Inc. v. Helping Hands
    Lifeline Found., Inc., 
    949 S.W.2d 707
    , 713 (Tex. App. 1997); Lum v. State, 
    903 S.W.2d 365
    , 369-70 (Tex. App. 1995); Regal Petrol. Corp. v. McClung, 
    608 S.W.2d 276
    , 278
    (Tex. Civ. App. 1980); Williams v. Hemphill County, 
    254 S.W.2d 839
    , 842 (Tex. Civ.
    App. 1952). In Louisiana, an expert, who by education or experience has a unique
    43
    No. 32381-1-111
    Driggs v. Howlett, MD.
    knowledge of the subject matter at issue, is permitted to express personal opinions.
    Barrett v. T.L. James & Co., 28, 170 (La. App. 2 Cir. 4/3/96); 
    671 So. 2d 1186
    , 1194;
    cert. denied, 96-1124 (La. 6/7/96); 
    674 So. 2d 973
    ; Blitz v. Jefferson Parish Hosp. Serv.
    Dist. No. 2, 93-733 (La. App. 5 Cir. 4/14/94) 
    636 So. 2d 1059
    . In Florida, an expert's
    personal opinion need not meet the Frye test for admissibility. Rickgauer v. Sarkar, 
    804 So. 2d 502
    , 504 (Fla. Dist. Ct. App. 2001 ).
    In Wardv. Dale County Farmers Co-op, Inc., 
    472 So. 2d 978
    , 978-79 (Ala. 1985),
    the reviewing court affirmed the trial court's admittance of testimony of a county agent
    concerning the cause of a low quality of crop. The agent referenced his opinion as a
    personal opinion, but the opinion was based on his experience as an agricultural agent. In
    Arkansas State Highway Commission v. Union Planters National Bank, 
    231 Ark. 907
    ,
    915, 
    333 S.W.2d 904
    (1960), the appellate court affirmed the trial court's admission of an
    expert witness on land values, despite mention that the opinion was a personal opinion.
    The court wisely noted that the opinion of any expert is of course personal to that
    witness.
    This admissibility of personal opinions of an expert witness is not limited to
    southern states. In Joyce v. Boulevard Physical Therapy & Rehabilitation Center, PC,
    
    694 A.2d 648
    , 655 (Pa. Super. Ct. 1997), the trial court concluded that the expert
    testimony provided by one physician did not address the course of conduct that an
    average orthopedic surgeon would undertake during the course of the patient's treatment,
    44
    No. 32381-1-III
    Driggs v. Howlett, MD.
    but rather contained the witness' personal thoughts about the standard of care. The trial
    court excluded testimony because the plaintiffs expert testified in the first person when
    articulating the standard of care and he testified to his personal opinion, rather than an
    objective standard of care. The appeals court disagreed that the expert testifying in the
    first person transformed his elicitation of the standard of care into his personal opinion.
    The expert's opinion was admissible since it was based on his experience and training as
    an orthopedic surgeon.
    Harmless Error
    Providence Physician Services contends that, assuming the trial court's exclusion
    of Dr. Lawrence Menendez's opinions is error, the error was harmless. Providence
    underscores the fact that Dr. Steven Graboff testified to each opinion of Lawrence
    Menendez that the trial court excluded. Therefore, Providence argues the excluded ·
    testimony of Menendez would have been cumulative.
    When a trial court makes an erroneous evidentiary ruling, the question on appeal
    becomes whether the error was prejudicial, for error without prejudice is not grounds for
    reversal. Brown v. Spokane County Fire Prot. Dist. No. l, 
    100 Wash. 2d 188
    , 196, 668 P .2d
    571 (1983); Mut. ofEnumclaw Ins. Co. v. Gregg Roofing, Inc., 
    178 Wash. App. 702
    , 728-
    29, 315 P .3d 1143 (2013 ). An error will be considered harmless unless it affects the
    outcome of the case. State v. Jackson, 
    102 Wash. 2d 689
    , 695, 
    689 P.2d 76
    (1984); 
    Brown, 100 Wash. 2d at 196
    . A harmless error is an error which is trivial, or formal, or merely
    45
    No. 32381-1-111
    Driggs v. Howlett, MD.
    academic, and was not prejudicial to the substantial rights of the party assigning it, and in
    no way affected the final outcome of the case. Anfinson v. FedEx Ground Package Sys.,
    Inc., 
    159 Wash. App. 35
    , 44, 
    244 P.3d 32
    (2010), aff'd, 
    174 Wash. 2d 851
    , 
    281 P.3d 289
    (2012).
    Error will be considered prejudicial if it presumptively affects the outcome· of the
    trial. James S. Black & Co. v. P&R Co., 
    12 Wash. App. 533
    , 537, 
    530 P.2d 722
    (1975).
    When the reviewing court is unable to know what value the jury placed on the improperly
    admitted evidence, a new trial is necessary. Thomas v. French, 
    99 Wash. 2d 95
    , 105, 
    659 P.2d 1097
    (1983); Smith v. Ernst Hardware Co., 
    61 Wash. 2d 75
    , 80, 
    377 P.2d 258
    (1962);
    State v. Murphy, 
    7 Wash. App. 505
    , 508-10, 
    500 P.2d 1276
    (1972). The rule should be the
    same when the appeals court may not judge what value a jury may place on improperly
    excluded evidence.
    We agree with Providence Physician Services that normally exclusion of
    cumulative evidence is harmless. Improper admission of evidence constitutes harmless
    error if the evidence is cumulative. Hoskins v. Reich, 
    142 Wash. App. 557
    , 570, 
    174 P.3d 1250
    (2008). A factor to consider when determining harmless error is whether excluded
    evidence involved cumulative evidence. State v. Johnson, 
    124 Wash. 2d 57
    , 76, 
    873 P.2d 514
    (1994); Kimball v. Otis Elevator Co., 
    89 Wash. App. 169
    , 178, 
    947 P.2d 1275
    (1997).
    Probably all American jurisdictions follow this rule. People v. Fletcher, 
    328 Ill. App. 3d 46
    No. 32381-1-111
    Driggs v. Howlett, MD.
    1062, 1071-72, 
    768 N.E.2d 72
    , 
    263 Ill. Dec. 312
    (2002); Gonzalezv. Stevenson, 
    791 S.W.2d 250
    , 253 (Tex. App. 1990).
    We decline to follow the cumulative evidence rule in this appeal for three reasons.
    First, the excluded opinions of Dr. Lawrence Menendez probed the central issues in
    dispute in this case. Menendez's opinions included whether Dr. Andrew Howlett's
    treatment fell below the standard of care, whether that negligent treatment proximately
    caused Driggs' harm, and whether the risk of harm from the surgery was so material that
    a reasonable patient would have wanted disclosure and would have chosen different
    treatment.
    Second, the jury garnered the misimpression that Dr. Lawrence Menendez lacked
    opinions on these key issues. During closing argument, Providence Physician Services
    highlighted that Lawrence Menendez provided no opinions on these key issues. Of
    course, Providence did not disclose to the jury that Menendez held opinions but the
    opinions were excluded from their hearing.
    Third, in addition to noting the absence of opinions from Dr. Menendez,
    Providence excoriated the credentials and credibility of Dr. Steven Graboff, the other
    physician who provided the same favorable testimony as Lawrence Menendez.
    Providence's own words during closing argument concerning Graboffs character as an
    unqualified, disgraced, hired gun, whose opinions cannot be believed, illustrate the harm
    of the exclusion of Lawrence Menendez's opinions. None of the reported decisions,
    47
    No. 32381-1-III
    Driggs v. Howlett, MD.
    wherein the court holds harmless exclusionary error with regard to cumulative evidence,
    concern these three factors.
    One foreign decision of limited relevance is Harper v. Roberts, 
    173 Ohio App. 3d 560
    , 2007-0hio-5726, 
    879 N.E.2d 264
    . Home owners sued roof contractors for breach of
    contract in connection with the construction of a new roof that leaked during rainfall.
    The jury ruled in favor of the contractors and the Court of Appeals reversed and
    remanded for a new trial. The reviewing court held that the trial court committed error
    during a "biased" questioning of the owners and their expert witness. More importantly,
    the error was prejudicial because the case depended on the credibility of the witnesses.
    In this appeal, with the credibility of Steven Graboff impugned, Dr. Lawrence
    Menendez's testimony grew critical. The error in excluding Dr. Menendez's testimony
    was not harmless. On this basis, we reverse the jury's verdict and remand for a new trial
    consistent with this opinion.
    Jury Instructions
    Joshua Driggs also contends that he is entitled to a new trial because the trial court
    refused to instruct the jury that Physician's Assistant Brandi DeSaveur was an agent of
    Providence Physician Services. Providence argues that the instructions were proper
    because Driggs never alleged negligence by DeSaveur in his complaint. In tum, Driggs
    contends he placed Providence on notice of his protest about DeSaveur' s performance.
    Providence Physician Services also contends the trial court committed no error by
    48
    No. 32381-1-111
    Driggs v. Howlett, MD.
    denying use of a jury instruction naming Brandi DeSaveur because no competent expert
    testified that DeSaveur breached the duty of care of a physician's assistant. Joshua
    Driggs responds that Grabo ff was competent to testify regarding Brandi DeSaveur' s
    standard of care and he criticized her for failure to notice the fracture. In tum,
    Providence contends that Dr. Graboff, as a physician, was not qualified to testify to the
    standard of care of a physician's assistant. Joshua Driggs argues that DeSaveur
    negligently performed a task that only an orthopedic surgeon should perform,and that
    Providence should not be able to disclaim DeSaveur' s actions by holding her to a lower
    standard of care. Neither party cites a case that addresses whether a physician may testify
    to the standard of care of a physician's assistant or whether anyone other than a
    physician's assistant may testify to the standard of care of a physician's assistant.
    We have granted Joshua Driggs a new trial on other grounds. Therefore, we
    decline to address issues surrounding the assignment of error concerning instructing the
    jury with regard to negligence of Brandi DeSaveur. Principles of judicial restraint dictate
    that if resolution of another issue effectively disposes of a case, we should resolve the
    case on that basis without reaching the second issue presented. Wash. State Farm Bureau
    Fed'n v. 
    Gregoire, 162 Wash. 2d at 307
    (2007); Hayden v. Mut. ofEnumclaw Ins. 
    Co., 141 Wash. 2d at 68
    (2000).
    On remand, each party may request the trial court for instructions or relief as to
    whether or not the question of Brandi DeSaveur's conduct should be an issue for the
    49
    No. 32381-1-111
    Driggs v. Howlett, MD.
    second trial and whether or not Brandi DeSaveur should be listed on a jury verdict as an
    actor of Providence Physician Services. We also decline to address what standard of care
    to impose on a physician's assistant. The parties should first thoroughly brief and
    analyze this issue with the trial court.
    CONCLUSION
    We vacate the judgment entered in favor of Providence Physician Services and Dr.
    Andrew Howlett. We remand for a new trial with directions to permit Dr. Lawrence
    .
    Menendez to testify to his opinions of the standard of care, causation, and the extent of
    the risk in leaving the allograft unattached to fixation.
    A majority of the panel has determined this opinion will not be printed in the
    Washington Appellate Reports, but it will be filed for public record pursuant to RCW
    2.06.040.
    F~l(f.
    WE CONCUR:
    50