UNITED STATES COURT OF APPEALS FOR VETERANS CLAIMS

                                           No. 18-0495

                               ELIZABETH M. WALSH, APPELLANT,

                                                V.

                                    ROBERT L. WILKIE,
                         SECRETARY OF VETERANS AFFAIRS, APPELLEE.

                        On Appeal from the Board of Veterans' Appeals

                                  (Decided February 24, 2020)

       Kaitlyn C. Degnan, of Providence, Rhode Island, was on the brief for the appellant.

        Richard J. Hipolit, Acting General Counsel; Mary Ann Flynn, Chief Counsel; Christopher
W. Wallace, Deputy Chief Counsel; and Ronen Morris, all of Washington, D.C., were on the brief
for the appellee.

       Before BARTLEY, Chief Judge, and PIETSCH and TOTH, Judges.

       TOTH, Judge: A veteran is entitled to disability compensation when a service-connected
disability causes or aggravates a non-service-connected disability. In a precedent opinion, the VA
General Counsel (G.C.) determined that obesity, although itself not a disability for which
compensation may be awarded, can constitute an "intermediate step" in demonstrating service
connection on a secondary basis for another condition.
       Elizabeth M. Walsh appeals the Board's denial of service connection for hypertension and
sleep apnea. The question raised in this case is whether this "intermediate step" is limited to
situations in which a service-connected disability causes obesity—the hypothetical situation used
by the G.C. opinion—or also embraces situations in which a service-connected disability
aggravates obesity. We conclude that, whatever the phrasing of the G.C. opinion, there is no legal
basis to recognize a causal relationship but not an aggravating one in these circumstances. Because
the December 2017 Board decision relied on a medical opinion that did not adequately address
whether secondary service connection for hypertension and sleep apnea was warranted based on a
theory that the veteran's obesity was aggravated by service-connected conditions, we vacate and
remand for further proceedings.
        Ms. Walsh served on active duty for training in the Army Reserves from January to June
1978. During this period, she fell and injured both knees. In September 1978, she was granted
service connection for bilateral chondromalacia, a breakdown of cartilage in the knee joint that
causes pain when bones rub together.1 In the years that followed, the bilateral knee ratings were
increased and service connection was also granted for, among other things, arthritis in both hips
and a low back disability. Per the veteran, because of pain and the soporific effects of prescribed
pain medication, these conditions severely limited her mobility.
        In June 2009, Ms. Walsh sought disability compensation for hypertension and a "sleeping
condition" as secondary to her service-connected knee, hip, and back conditions. R. at 3158. The
VA regional office denied the claims and she appealed. While appellate litigation proceeded, the
veteran underwent a VA sleep study, which diagnosed mild obstructive sleep apnea. In an April
2014 report, a VA examiner opined that Ms. Walsh's sleep apnea was "likely due to her
documented weight gain/obesity" and that the onset of hypertension coincided with "increased
weight/obesity." R. at 1694-95. But the examiner opined that neither sleep apnea nor hypertension
was caused or aggravated by service-connected knee, hip, or back conditions. VA continued to
deny the claims.
        The Board remanded the claims in May 2016. Noting the veteran's reports that she was a
"very athletic and active adult" before her service-connected disabilities began and the most recent
examiner's attribution of sleep apnea and hypertension to obesity, the Board sent the service-
connection claims back for a new etiology opinion. Specifically, it asked for an examiner to
address whether it was at least as likely as not that Ms. Walsh's obesity, which was "noted as the
cause" of her hypertension and sleep apnea, was either caused or aggravated by service-connected
disabilities. R. at 676-77.
        While VA was attempting to obtain such an opinion, G.C. Precedent Opinion 1-2017 was
issued, which discussed the potential for disability compensation based on obesity. As a
preliminary matter, the opinion generally determined that obesity itself was ineligible for service
connection on direct or secondary bases because it did not qualify as a disease or injury. G.C. Prec.
Op. 1-2017, at 2-7 (Jan. 6, 2017).2 (We subsequently held that we lacked jurisdiction to consider

        1
         Knee Pain (Chondromalacia Patella), CLEVELAND CLINIC, https://my.clevelandclinic.org/health/diseases/
15607-knee-pain-chondromalacia-patella.
        2
            Available at https://www.va.gov/OGC/docs/2017/VAOPGCPREC1-2017.pdf. The opinion recognized the



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a challenge to this determination because it would entail impermissible judicial review of the rating
schedule's content. Marcelino v. Shulkin, 

, 157-58 (2018) (citing 38 U.S.C. §
7252(b)).) The G.C. opinion nevertheless reasoned that "[o]besity may be an 'intermediate step'
between a service-connected disability and a current disability that may be service connected on a
secondary basis under 38 C.F.R. § 3.310(a)." G.C. Prec. Op. 1-2017, at 2-3. Somewhat presciently
for our purposes, the opinion used the example of a veteran seeking service connection for
hypertension on the theory that the "veteran's service-connected back disability causes obesity due
to lack of exercise, which leads to hypertension." 

        Under 38 C.F.R. § 3.310(a), disability which is proximately due to or the result of
        a service-connected disease or injury is service connected. "Proximate cause" is
        defined as a "cause that directly produces an event and without which the event
        would not have occurred." When there are potentially multiple causes of a harm,
        an action is considered to be a proximate cause of the harm if it is a substantial
        factor in bringing about the harm and the harm would not have occurred but for the
        action.

        A determination of proximate cause is basically one of fact, for determination by
        adjudication personnel. With regard to the hypothetical presented in the previous
        paragraph, adjudicators would have to resolve the following issues: (1) whether the
        service-connected back disability caused the veteran to become obese; (2) if so,
        whether the obesity as a result of the service-connected disability was a substantial
        factor in causing hypertension; and (3) whether the hypertension would not have
        occurred but for obesity caused by the service-connected back disability. If these
        questions are answered in the affirmative, the hypertension may be service
        connected on a secondary basis.

(citations and some quotation marks omitted). Thus, the first step asks about the
connection between a service-connected disability and obesity, while the second and third steps
ask about the connection (proximate and but-for causation) between obesity and the disability for
which secondary service connection is sought.
        VA eventually obtained a medical opinion, but because it did not align with the framework
set out in the G.C. opinion, VA sought another one. In its opinion request, VA asked (under the
"at least as likely as not" standard): (1) whether the veteran's service-connected disabilities,
including medications prescribed to treat them, "caused" the veteran to gain weight or become


potential to award extraschedular compensation in a particular case where "obesity resulting from a service-connected
disease or injury is found to produce impairment beyond that contemplated by the applicable provisions of VA's rating
schedule" for the service-connected disability. G.C. Prec. Op. 1-2017, at 1.



                                                         3
obese; (2) if so, whether the weight gain or obesity resulting from the service-connected disability
was a substantial factor in "causing" hypertension or sleep apnea; and (3) again, if so, whether
hypertension or sleep apnea would not have occurred but for weight gain or obesity "caused" by
the service-connected disability. R. at 21. If the medical expert answered "yes" to these three
questions with respect to one of the conditions (hypertension or sleep apnea) but not the other, VA
asked the expert to further address whether the other condition was "proximately due to" or
"aggravated (permanently worsened beyond the natural progress of the disease)" by the now-
service-connected condition or its medications.3 

opinion was provided in July 2017 by a physician who was on the staff of
the local VA medical center and an assistant professor of medicine at a nearby university. After
fully listing all service-connected disabilities, she said with respect to the first question that she
couldn't state "with greater than 50% probability" that such disabilities "contributed to obesity."
R. at 17. As relevant here, she observed that
        there is a complex interaction between energy expenditure and caloric intake.
        Obesity develops over a period of time. Physical activity, caloric intake, genetic
        factors, microbiome are all important factors. A recent longitudinal study that
        evaluated the cause of obesity noted that physical activity decreased the probability
        of being overweight by 4.3-6.5% based on a linear model but did not support the
        causal link between Leisure Time Physical activity and [being] overweight.

"proximate cause" language of G.C. Opinion 1-2017, the physician said she
couldn't state, based on the current evidence and medical literature, "that there is a cause-effect
relationship between arthritis of the back or of the knee and obesity." 

the second
question, the physician advised that obesity is "a significant factor that causes obstructive sleep
apnea [and] hypertension." R. at 18. Last, the physician opined that it was as likely as not that sleep
apnea and hypertension "would not have occurred but for" obesity. R. at 19. (Given her responses
to the first three questions, the physician did not answer the remaining ones.) She concluded that,
although there is evidence that obesity is "related to hypertension and sleep apnea," "there is no
clear-cut evidence that decreased physical activity secondary to arthritis is causally related to
[o]besity." 

Court recently clarified in Ward v. Wilkie, 

, 237-38 (2019), that the proper standard in
an aggravation inquiry is not whether there was "permanent worsening" but rather "any increase" in disability.



                                                         4
       The Board relied on the physician's opinion for the conclusion that "obesity cannot be
attributed to [the veteran's] service-connected disabilities" and denied service connection for
hypertension and sleep apnea on a secondary basis. R. at 7. The medical opinion was adequate and
probative, the Board found, because it was "unequivocally stated" and "supported by the evidence
of record and a detailed rationale." 

followed.
       Ms. Walsh makes several arguments on appeal. Among these, she contends that the
analysis set out in G.C. Opinion 1-2017 requires a determination of whether obesity was caused
or aggravated by a service-connected disability and that the 2017 VA medical opinion fails to
address aggravation. Appellant's Br. at 9-11. The Secretary does not directly address this argument,
stating instead that the 2017 medical opinion "provided the Board with the information it needed
to make a fully informed decision" and that Ms. Walsh "does not challenge the propriety of the
General Counsel opinion or show how the [medical] expert deviated from the relevant and required
analysis." Secretary's Br. at 8. G.C. Opinion 1-2017 does not mention the concept of aggravation
in the portion that discusses obesity as an "intermediate step" and references only subsection (a)
of 38 C.F.R. § 3.310. Nevertheless, the principles contained in § 3.310 make any distinction in
G.C. Opinion 1-2017 between causation and aggravation legally untenable.
       As an initial matter, we note that G.C. precedent opinions are issued by VA's chief legal
officer and are binding on the Board. 38 U.S.C. § 7104(c). They are not, however, binding on the
Court. Molitor v. Shulkin, 

, 408 (2017). Instead, because such opinions lack the
formalities of notice-and-comment rulemaking, the Court defers to them in accordance with their
"'power to persuade.'" Wanless v. Shinseki, 

, 1338 (Fed. Cir. 2010) (quoting
Skidmore v. Swift & Co., 

, 140 (1944)).
       To properly analyze Ms. Walsh's arguments with respect to G.C. Opinion 1-2017, we must
start with the language of the regulation governing secondary service connection. Section 3.310
first provides that "disability which is proximately due to or the result of a service-connected
disease or injury shall be service connected." 38 C.F.R. § 3.310(a) (2019). This describes a causal
relationship. See MacPhee v. Nicholson, 

, 1327 (Fed. Cir. 2006). In the next
subsection, the regulation specifies that "[a]ny increase in severity of a nonservice-connected
disease or injury that is proximately due to or the result of a service-connected disease or injury,
and not due to the natural progress of the nonservice-connected disease, will be service connected."
38 C.F.R. § 3.310(b). This, as the provision itself recognizes, describes an aggravating relationship.



                                                  5
See 

language in these provisions is essentially identical. Both discuss something
that "is proximately due to or the result of a service-connected disease or injury" and advise that
this "shall [or will] be service connected." Nothing in this language justifies a distinction between
causation and aggravation in the first step of the analysis in G.C. Opinion 1-2017.
        Aside from (b)'s "natural progress" clause, the only difference between the two subsections
is the subject of the operative language: in (a) it is a "disability," whereas in (b) it is an "increase
in severity of a nonservice-connected disease or injury." But, for purposes of the present inquiry,
these terms are conceptually synonymous. Our decision in Allen v. Brown, 

, 448
(1995) (en banc), makes clear that "when aggravation of a veteran's non-service-connected
condition is proximately due to or the result of a service-connected condition, such veteran shall
be compensated for the degree of disability (but only that degree) over and above the degree of
disability existing prior to the aggravation."4 In other words, aggravation is just causation of an
increase in disability—i.e., a discrete portion of disability—rather than of the whole disability
itself. Thus, Allen held that the term "disability" includes "any additional impairment of earning
capacity resulting from an already service-connected 

. The remainder
of subsection (b) bears this out. It instructs VA adjudicators to "determine the baseline and current
levels of severity under the Schedule for Rating Disabilities . . . and determine the extent of
aggravation by deducting the baseline level of severity, as well as any increase in severity due to
the natural progress of the disease, from the current level." 38 C.F.R. § 3.310(b). Therefore, the
fact that subsection (b) uses the phrase "increase in severity of a nonservice-connected disease or
injury" rather than "disability," as appears in subsection (a), is of no legal moment.
        In short, there is no permissible basis in the relevant regulation for concluding that obesity
may be an "intermediate step" in a secondary-service-connection analysis when service-connected
disability causes it, but not when service-connected disability aggravates it. So, where does that
leave G.C. Opinion 1-2017? The Secretary's brief is carefully agnostic as to whether G.C. Opinion
1-2017 takes a position on the aggravation-of-obesity issue and, if so, whether that position is



        4
            Allen's conclusion was based on a reading of the relevant statutes. Before Allen, "VA paid compensation
for a disability on a secondary basis only if the secondary condition was entirely caused by a service-connected
disability." Claims Based on Aggravation of a Nonservice-Connected Disability, 62 Fed. Reg. 30,547, 30,547 (June
4, 1997) (proposed rule) (emphasis added).




                                                        6
consistent with § 3.310. Importantly, the Board may not rely on a G.C. opinion that is inconsistent
with a valid regulation. See, e.g., Franklin v. Brown, 

, 192-93 (1993).
        Based on our review of G.C. Opinion 1-2017, however, we discern no necessary
inconsistency between it and § 3.310 on this issue. 5 It's true that the portion of the opinion
addressing obesity as an "intermediate step" in the secondary-service-connection context never
mentions aggravation. But we do not read that omission as an affirmative position that aggravation
is a legally irrelevant consideration. G.C. Opinion 1-2017 provides guidance on how to analyze
obesity as an "intermediate step" using a hypothetical "example" in which a "service-connected
back disability causes obesity due to lack of exercise, which leads to hypertension." G.C. Prec. Op.
1-2017, at 9. The causal relationship between the service-connected condition and obesity
(causation) is no more integral to the opinion's analytic framework than is the identity of the
service-connected condition (a back disability). This can be seen by substituting aggravation for
causation in the hypothetical as follows: (1) whether the service-connected back disability
aggravated the veteran's obesity; (2) if so, whether the aggravation of obesity as a result of service-
connected disability was a substantial factor in causing hypertension; and (3) whether the
hypertension would have occurred but for obesity aggravated by the service-connected back
disability. Cf. 

inquiry is consistent with both the legal principles of § 3.310(b) and the
analytic principles sketched out by the General Counsel.
        In other words, properly construed, G.C. Opinion 1-2017 does not purport to prohibit
inquiry into whether a service-connected disability aggravates a veteran's obesity. And for good
reason, as this would contradict VA's aggravation regulation. So, to be clear: Despite the G.C.
opinion's silence regarding aggravation, the Board, in accordance with § 3.310(b), must consider
aggravation in this context when the theory is explicitly raised by the veteran or reasonably raised
by the record.
        With this legal matter resolved, we turn to the Board decision here. We conclude that the
Board clearly erred in finding the 2017 VA medical opinion adequate. Among other requirements,
to be adequate, a VA medical opinion must address the medical question at issue in enough detail
that the Board can make a fully informed evaluation of the claim. Atencio v. O'Rourke, 

, 89 (2018). Here, the Board found in its May 2016 remand that the evidence of record

        5
          Ms. Walsh's appeal does not implicate, and we have no occasion to address, any other aspect of G.C.
Opinion 1-2017's analysis.



                                                     7
necessitated a medical opinion as to whether service-connected disability caused or aggravated
her obesity. R. at 676-77. But the 2017 opinion on which it relied is silent on the question of
aggravation of obesity. To the extent the Board thought, after issuance of G.C. Opinion 1-2017,
that a medical opinion—on whether service-connected disability aggravated Ms. Walsh's
obesity—was no longer legally relevant, the present opinion dispels that misconception. But the
fact remains that the physician was not asked for a medical opinion on the question of aggravation
and her report provides no information on which the Board can rely to adjudicate that theory of
service connection. Thus, the Board clearly erred in finding the 2017 VA opinion adequate to
decide these claims. We remand for the Board to obtain a new medical opinion that provides
sufficient information on relevant medical issues—such as whether service-connected knee, hip,
and back disabilities caused or aggravated Ms. Walsh's obesity—to allow it to make a "fully
informed" decision on the hypertension and sleep apnea claims. 

.
       Finally, we note that Ms. Walsh makes several other arguments, such as that the 2017 VA
medical opinion was inadequate because the physician used improperly high standards when
resolving medical questions and that the Board clearly erred in finding that she did not have a
current sleep apnea disability. (Regarding this last assertion, she points to a February 2013 VA
diagnostic polysomnography report diagnosing mild obstructive sleep apnea and prescribing
continuous positive airway pressure therapy. R. at 771-72.) Given our determination that remand
is already warranted, we need not resolve those arguments now, nor do we think they are
appropriate for resolution in a precedential decision. We trust that the Board, as part of its
obligation on remand to provide a critical reassessment of the claims, see Roberts v. McDonald,

, 113-14 (2014), will duly consider these arguments and all relevant legal and
factual disputes.
       The December 8, 2017, Board decision is VACATED and the claims are REMANDED for
further proceedings consistent with this opinion.




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