case involves a medical malpractice action for a lost chance
of a better outcome. The parties jointly sought direct
discretionary review under RAP 2.3(b)(4), challenging two
pretrial rulings. Two questions of law are before us: (1)
whether a court should use a "but for" or
"substantial factor" standard of causation in loss
of chance cases and (2) whether evidence relating to a
contributory negligence defense should be excluded based on
the plaintiffs failure to follow his doctor's
instructions. The trial court decided that the but for
standard applies and the contributory negligence defense was
not appropriate in this case. We affirm in part and reverse
and Procedural History
September 1, 2011, David Dunnington saw his primary care
provider, Dr. William Kirshner, reporting that he had a
lesion on the plantar surface of his left foot that arose
after a puncture wound. Dr. Kirshner arranged an appointment
with Dr. Alvin Ngan, a podiatrist at Virginia Mason Medical
Center. Dr. Ngan saw Dunnington the same day and diagnosed
the lesion as a pyogenic granuloma-a benign lesion.
Ngan recommended two courses of possible treatment: it could
be surgically excised or conservatively treated with
cryotherapy. Dunnington chose the conservative treatment. Dr.
Ngan administered the treatment and instructed Dunnington to
return in 10 days. When Dunnington returned on September 15,
2011, the lesion appeared recalcitrant. Dr. Ngan once again
informed Dunnington of his options, which included surgical
excision and biopsy. Dr. Ngan favored surgical excision, but
Dunnington chose conservative treatment. Dr. Ngan instructed
Dunnington to return in 10 days, but he did not. On December
16, 2011, Dunnington contacted Dr. Ngan, complaining of
continued soreness, and requested an MRI that was performed
on December 26, 2011. When Dunnington returned to the clinic
the following day to discuss the results of his MRI, Dr. Ngan
noticed the lesion was enlarged from the previous visit and
he recommended surgical excisional biopsy. Dr. Ngan did not
suspect cancer. Dunnington deferred making a decision because
he wanted to discuss the issue with his family. Dunnington
then saw Dr. Ryan Bierman, seeking a second opinion regarding
the surgical excision. Dr. Bierman also diagnosed the lesion
as a benign, trauma-induced pyogenic granuloma. They
discussed all options, including surgical excision and
biopsy, but Dunnington chose conservative treatment once
more. On January 31, 2012, Dunnington consulted a
dermatologist, Dr. Arlo Miller, who performed a punch biopsy.
This resulted in a positive finding of melanoma. On February
16, 2012, Dunnington underwent surgical excision and the
cancer was removed. However, the melanoma recurred.
Dunnington went through chemotherapy and radiation treatment,
which proved unsuccessful, and the cancer recurred.
Dunnington's left leg ultimately had to be partially
amputated. He now appears to be cancer free.
brought a medical negligence action against Virginia Mason
alleging that Dr. Ngan was negligent in Dunnington's
diagnosis, which deprived him of a 40 percent chance that the
melanoma would not recur had a proper diagnosis and treatment
occurred. The defendant, Virginia Mason, asserted an
affirmative defense of contributory negligence based on
Dunnington's delay in returning for follow up care and
his decision to seek a second opinion rather than undergo the
recommended excision and biopsy. Dunnington moved to strike
the affirmative defense or for partial summary judgment.
Based on declarations, the court granted the motion, which
the parties treat as a grant of partial summary judgment.
Virginia Mason's motion for reconsideration was denied.
The trial court also granted Dunnington's motion for a
loss of chance jury instruction, but denied his request for a
substantial factor test instruction. Instead, the court
determined that a but for causation standard is the
appropriate legal standard. The parties jointly sought
discretionary review of Dunnington's challenge to the
loss of chance and substantial factor jury instruction and
Virginia Mason's challenge to the trial court's
dismissal of the contributory negligence defense.
first recognized the lost chance of a better outcome cause of
action in Herskovits v. Group Health Cooperative of Puget
Sound, 99 Wn.2d 609, 664 P.2d 474 (1983) (plurality
opinion). Although a majority in that case recognized the
cause of action, several opinions were authored and no
opinion garnered five votes: the lead opinion by Justice Dore
collected one supporting vote and a concurring opinion by
Justice Pearson collected three votes. Although both of these
opinions recognized the cause of action, they differed on its
characterization. Most recently, in Mohr v.
Grantham, 172 Wn.2d 844, 262 P.3d 490 (2011), we
revisited this issue and expressly adopted Justice
Pearson's analysis. Mohr contains a detailed and
comprehensive discussion of the cause of action, the
principles underlying the doctrine, and how the cause of
action fits in our traditional and general tort principles of
medical malpractice, including duty, breach, injury, and
proximate cause. Mohr, 172 Wn.2d at 850-57.
Mohr, the plaintiff suffered a trauma-induced stroke
and was permanently disabled. At the hospital, Mrs. Mohr
suffered neurological symptoms but the physician failed to
immediately treat her. Expert opinion established that she
would have had a 50-60 percent chance of a better outcome
with nonnegligent treatment. There, we adopted the
characterization and analysis of the cause of action from the
Herskovits concurrence and continued by noting,
A plaintiff making such a claim must prove duty, breach, and
that there was an injury in the form of a loss of a chance
caused by the breach of duty. To prove causation, a plaintiff
would then rely on established tort causation doctrines
permitted by law and the specific evidence of the case.
Mohr, 172 Wn.2d at 862 (emphasis added). By
emphasizing the basic requirement of tort law, we implicitly
recognized that generally a but for test is the applicable
standard. While we did not conclusively reject a relaxed
causation standard, we suggested in Mohr that
general tort law principles apply.
held in certain circumstances the substantial factor standard
is appropriate to use:
First, the test is used where either one of two causes would
have produced the identical harm, thus making it impossible
for plaintiff to prove the "but for" test. In such
cases, it is quite clear that each cause has played so
important a part in producing the result that responsibility
should be imposed on it. Second, the test is used where a
similar, but not identical, result would have followed
without the defendant's act. Third, the test is used
where one defendant has made a clearly ...