Establishing disability of non -service connected disabitlity secondary to service connected disability
In Wallin, this Court held that establishing a nexus between a service connected disability and the current disability is all that is required for a veteran to be disabled under 3.310:
“In order to establish entitlement to service connection on a secondary basis, there must be (1) evidence of a current disability; (2) evidence of a service connected disability; and (3) medical evidence establishing a nexus between the service connected disability and the current disability.” See Wallin v. West, 11 Vet. App. 509, 512 (1998).
The Court in Wallin envisioned that once a medical nexus was established between the service connected disabilities and the non-service connected disabilities the veteran met his burden of establishing service connection. The burden then shifts to the Secretary to explain why such a nexus is insufficient to establish causation. To be clear, Webster’s Dictionary describes “nexus” as a causal link; “for example, the nexus between poverty and crime.”
This Court recognized in Sacks v. West, 11 Vet.App. 314, 316 (1998). that treatises “can provide important support when combined with an opinion of a medical professional.” Id. at 317. Furthermore, Sacks observed that even without accompanying medical opinion, a medical article or treatise, standing alone, may provide sufficient evidence of a causal connection when it “discusses generic relationships with a degree of certainty” so that the causal connection is “based upon objective facts rather than on an unsubstantiated lay medical opinion.”
The VA often concedes that PTSD is associated to high degree with obstructive sleep apnea but then holds that this is not sufficient to establish causation. Therefor it is important to discuss association and causation in the medical sciences.
The Institute of Medicine (IOM) has already established what causation is. The IOM was charged in determining if Agent Orange is the cause of multiple disabling conditions among veterans who served in Vietnam. It concluded that certain conditions including diabetes and ischemic heart disease were caused by Agent Orange. Now, they did not determine scientifically how exposure to Agent Orange results in the development of diabetes. What the IOM did was identify an association between diabetes and service in Vietnam. The IOM compared the incidence of diabetes in veterans who served in Vietnam to the incidence of diabetes in veterans who did not serve in Vietnam. Since the incidence of diabetes in the Vietnam veteran group was higher than that of the control group, it was determined that Agent Orange was the cause of diabetes in this group
In science association is prima facie evidence for causation, and the lack of association is prima facie evidence for lack of causation. Once association is established causation may be challenged by bias where the investigators had conflict of interest or the groups compared were dissimilar. Where association does exist the only way to dismiss it is by statistical analysis. Of note, the authors of the treatises provided in the IMO were all VA employees and the groups studied were all veterans with similar characteristics thus bias is clearly not a reason to suggest that association is not sufficient to determine causation. The second step is to ask whether the association noted merely arrived by chance. To answer this question science established statistical methods that require that the association must be certain to a degree of 95% to establish that the association is indeed causation.
The IOM reports: “Statistical techniques are also used to test specific hypotheses, particularly the null hypothesis that there is no association between exposure and disease in the population…The statistical tests related to the null hypothesis are referred to as significance tests, and the test results are commonly expressed in the form of a P value.” In medical studies the required P value is 95-99% certainty.
While scientists are careful to point out that correlation does not necessarily mean causation, scientists aspire to deal with absolute and statistical significance, which means at least 95% certainty and sometimes 99% certainty. Congress in establishing veteran disability legislation required that the association needs to be only “as likely as not” -50% rather than the 95% certainty required in scientific publications
The IOM provides an example of presumption of service connection for diabetics exposed to Agent Orange. In this case, the IOM provided benefits despite the low threshold of 50% probability shown by the studies.
“Consider a Vietnam veteran who develops diabetes. His service has been established as a potential risk factor based on findings of epidemiologic studies and knowledge that some Vietnam veterans were exposed to Agent Orange, leading to a presumption of exposure of all Vietnam veterans. However, other factors, such as obesity and age, also contribute to the development of diabetes. Service attribution for diabetes in this particular veteran is much more uncertain than for disability from the battle wound. The uncertainty comes both from gaps in the general evidence linking Agent Orange to diabetes and from limitations of the information available on exposure and other relevant characteristics for the particular veteran.”
While medical publications require that a study show 95-99% certainty that the two studied groups are truly different, this Court has already determined that the benefit of the doubt rule govern the certainty required for showing causation. In Wise (Court of Appeals for Veterans Claims in Wise v. Shinseki, 12-2764 (Vet. App. 2014, Precedential Status: Precedential)) held that “Congress has not mandated that a medical principle have reached the level of scientific consensus to support a claim.” The Court held:
“The foregoing raises the issue of whether the Board, in rejecting the potentially favorable medical literature of record because it espoused a medical principle that was not yet “generally accepted” in the scientific community, ran afoul of the benefit of the doubt rule…. In keeping with the benefit of the doubt rule, Congress has not mandated that a medical principle have reached the level of scientific consensus to support a claim for VA benefits. Instead, Congress, through the enactment of section 5107(b)’s low standard of proof for all issues material to a claim for veteran’s benefits, has authorized VA to resolve a scientific or medical question in the claimant’s favor so long as the evidence for and against that question is in “approximate balance.” Imposing a higher standard of proof would be counter to the benefit of the doubt rule. (See Jones v. Shinseki, 23 Vet. App. 382).”
This very low threshold of scientific proof was established by congress specifically for Veterans.
In Manio v. Derwinski this court held (emphasis added):
“Congress has designed and fully intends to maintain a beneficial non-adversarial system of veterans benefits. Congress expects VA to fully and sympathetically develop the veteran’s claim to its optimum before deciding it on the merits. Even then, VA is expected to resolve all issues by giving the claimant the benefit of any reasonable doubt. In such a beneficial structure there is no room for such adversarial concepts as cross examination, best evidence rule, hearsay evidence exclusion, or strict adherence to burden of proof. Congress has designed and fully intends to maintain a beneficial non-adversarial system of veterans benefits. This is particularly true of service-connected disability compensation where the element of cause and effect has been totally by-passed in favor of a simple temporal relationship between the incurrence of the disability and the period of active duty.” Manio v. Derwinski, 1 Vet. App. 140; 1991
In veterans’ disability a simple temporal relationship is sufficient to provide causation as required in section § 3.310 Disabilities that are proximately due to, or aggravated by, service-connected disease or injury.
In Mittleider v. West, 11 Vet. App. 181, 182 (1998), the Court quoted a passage from the Federal Register indicating that when it is not possible to separate the effects of a service-connected condition from non-service-connected conditions, “VA regulations at 38 C.F.R. § 3.102…clearly dictate that such signs and symptoms be attributed to the service-connected condition.”
The United States Court of Appeals for Veterans Claims stated in a case on appeal from the Board of Veterans’ Appeals (Decision March 23, 2006) (No. 04-0624 Howell v. Nicholson):
“See Mittleider v. West, 11 Vet.App. 181, 182 (1998) (holding that when claimant has both service connected and non-service-connected disabilities, Board must attempt to discern the effects of each disability and, where such distinction is not possible, attribute such effects to the service-connected disability); Schafrath, supra. The fact that Mr. Howell suffered from both service-connected and non-service-connected disabilities does not mean that he would not have required support sufficient to warrant aid and attendance or otherwise been permanently housebound based on his service connected disabilities alone. Moreover, if is not possible to evaluate separately the effects of each disability, application of the benefit-of-the-doubt doctrine requires the Secretary to attribute those inseparable to his service-connected disability. See Mittleider, supra.”