9
Service Connection on Aggravation and Secondary Bases
The Veterans’ Disability Benefits Commission asked the committee to
From a medical perspective, analyze the current Department of Veterans Affairs (VA) practice of assigning service connection on “secondary” and “aggravation” bases. In secondary claims, determine what medical principles and practices should be applied in determining whether a causal relationship exists between two conditions. In aggravation claims, determine what medical principles and practices should be applied in determining whether a preexisting disease was increased due to military service or was increased due to the natural process of the disease.
This chapter summarizes what is known about how aggravation of preservice disability and secondary claims are evaluated and rated, and provides recommendations on how the current process can be enhanced for each.
COMPENSATION FOR AGGRAVATION OF PRESERVICE DISABILITY CLAIMS
According to VA regulations, aggravation is defined as occurring under the following conditions:1
A preexisting injury or disease will be considered to have been aggravated by active military, naval, or air service, where there is an increase
in disability during such service, unless there is a specific finding that the increase in disability is due to the natural progress of the disease.
In the two-year period ending September 30, 2006, more than 21,000 veterans were service connected on the basis of aggravation of a preservice disability by military service, constituting less than two percent of disabilities that were service connected during that time period. The ten most common aggravated conditions (Table 9-1) accounted for nearly half of the total number of cases service connected on the basis of aggravation. Five percent were rated 50 percent or higher, while 87 percent were rated 20 percent or lower (Figure 9-1).
Establishing Preservice Disability
VA begins its evaluation of claims for aggravation of preservice disabilities under a “presumption of soundness” whereby, unless the evidence indicates otherwise, it is to be presumed that veterans were in sound condition on enlistment into service:
38 CFR §3.304(b), “Presumption of soundness.”
The veteran will be considered to have been in sound condition when examined, accepted, and enrolled for service, except as to defects, infirmities, or disorders noted at entrance into service, or where clear and unmistakable (obvious or manifest) evidence demonstrates that an injury or disease existed prior thereto and was not aggravated by such service. Only such conditions as are recorded in examination reports are to be considered as noted.
VA can note preservice illness or injury during a veteran’s service.2 For example, if the presence of disease residuals (e.g., scars, healed fractures) is discovered during service, and there is no evidence of the antecedent disease or injury during service, the conclusion is that the antecedent disease or injury preexisted service. Where this information is noted, and the evidentiary weight that is given to this information should the veteran file an aggravation claim in the future, are not clear.
Rating specialists consult medical records from before, during, and after a claimant’s enlistment date to evaluate claims involving preservice disability. Likely to be included in these records are findings from a general medical examination that rating specialists request for almost all new claims. According to the medical history section of the compensation and pension (C&P) examination worksheet for general medical exams, the physician should include in the report a discussion of “whether an injury
TABLE 9-1 10 Most Common Conditions Service Connected on the Basis of Aggravation, FY 2005–FY 2006
Diagnostic Code |
Disability |
Number of Cases |
6100 |
Hearing loss |
3,066 |
5276 |
Flat feet |
1,737 |
5260 |
Leg, limitation of flexion of |
1,043 |
5010 |
Traumatic arthritis |
832 |
5237 |
Lumbrosacral/cervical strain |
772 |
7101 |
Hypertensive vascular disease |
586 |
5242 |
Major depression |
572 |
5257 |
Knee, other impairment of |
538 |
6602 |
Bronchial asthma |
493 |
5271 |
Ankle, limited motion of |
485 |
SOURCE: Communication from Bradley G. Mayes, director, C&P Service, Department of Veterans Affairs, December 14, 2006. |

FIGURE 9-1 Distribution of grants for aggravation of preservice disability by rating degree from 0 to 100 percent, FY 2005–FY 2006.
SOURCE: Communication from Bradley G. Mayes, director, C&P Service, Department of Veterans Affairs, December 14, 2006.
or disease that is found occurred during active service, before active service, or after active service. To the extent possible, describe the circumstances, dates, specific injury or disease that occurred, treatment, follow-up, and residuals. If the injury or disease occurred before active service, describe any worsening of residuals due to being in military service.”3
If medical records indicate that the claimant had an illness or injury prior to enlistment, this will not confirm that the condition existed, but will be used as one piece of evidence in an overall evaluation “with due regard to accepted medical principles pertaining to the history, manifestations, clinical course, and character of the particular injury or disease or residuals thereof.”4
Under the presumption of soundness principle, if a preservice disability is not noted in the veteran’s medical records, VA has the burden of showing by clear and unmistakable evidence that the disease or injury existed prior to service, and was not aggravated by service.5
Aggravation vs. Natural Process of Disease
According to VA rating policy instructions, “Where the advancement in severity is beyond that to be expected by natural progress of the condition, service connection is warranted.6 This will require analysis of the facts in the individual case and knowledge of the particular condition concerned” (VA, 2005). In practice, when the presence of a preservice disability and an increase in that disability is established, rating specialists assume that the increase is due to aggravation by service, unless there is specific evidence indicating that the increase is due to the natural progress of the disease.
For veterans whose service was during wartime or peacetime after December 31, 1946, clear and unmistakable evidence (defined as “medical facts and principles that may be considered to determine whether the increase is due to the natural progress of the condition”) is required to rebut the presumption of aggravation.7
For veterans who served during peacetime prior to December 7, 1941, disease or injury will be found to be due to the natural progress of the condition when “available evidence of a nature generally acceptable as competent shows that the increase in severity of a disease or injury or
3 |
http://www.vba.va.gov/bln/21/Benefits/exams/disexm23.htm (accessed December 20, 2006). |
4 |
38 CFR 3.304(b)(1). |
5 |
VA’s Compensation and Pension Adjudication Procedures Manual (M21-1MR) is the Veterans Benefits Administration’s (VBA’s) manual for the disability determination process. The section on aggravation is attached as Appendix A of the manual. |
6 |
Phrases “natural process of disease” and “natural progress of disease” are used interchangeably throughout VA regulations and training materials. |
7 |
38 CFR 3.306(b). |
acceleration in progress was that normally to be expected by reason of the inherent character of the condition, aside from any extraneous or contributing cause or influence peculiar to military service.”8
The places, types, and circumstances of service are also taken into consideration for veterans who served during wartime. For example, if there are found to be manifestations of a preservice disease or injury during or soon after combat, or following status as a prisoner of war, aggravation of a preservice condition will be established.9 Hardships of service may also be considered in claims for veterans who served during peacetime.
Rating Aggravation of Preservice Disability Claims
The final rating of an aggravation claim takes into account the degree of disability over and above that which existed on entry into service. For instance, if a veteran has an overall rating of 90 percent and it can be ascertained from medical evidence that the degree of disability at entry into service was 10 percent, he or she will receive a final rating of 80 percent. If, however, the degree of disability at time of enlistment is not ascertainable, such a deduction will not be made and the veteran will receive the overall rating of 90 percent. When the overall rating at evaluation is 100 percent, the degree of preservice disability is never deducted.10
How rating specialists go about determining a veteran’s degree of disability prior to service compared with his or her current degree of disability is not clear. The physician performing the general medical examination is not responsible for assigning these percentages. The rater, therefore, through his or her own review of the medical records, most likely makes these determinations to make the deduction.
Temporary and intermittent flare-ups of illnesses or injuries that existed prior to service cannot be considered as aggravation due to service. A veteran is eligible for compensation only when his or her underlying condition (as opposed to symptoms) has been worsened by service. Also, should a veteran seek compensation for side effects (e.g., scars, absent or poorly functioning body parts) of medical or surgical treatment received during service for an illness or injury that existed preservice, his or her application will not be granted unless the preservice condition has otherwise been aggravated by service.11
Chronic and Hereditary Disease
Splane v. West (Fed. Cir. 2000) led to the November 7, 2002, publication of a final rule (67 FR 67792) amending VA’s adjudication regulations concerning presumptive service connection. Under the new rule, chronic illnesses that preexisted a veteran’s entry into service that manifest themselves to a degree of disability of at least 10 percent within a specified period after service are to be considered aggravated by service, unless there is evidence to the contrary. The specified period is within one year (except for leprosy and tuberculosis within three years, and multiple sclerosis within seven years) from the date of separation from service.12
The presumption may be rebutted by evidence showing that the chronic illness has not manifested itself to a degree of at least 10 percent within the specified period or, if it has, that the disability is due to a disease or injury acquired after separation from service.13
Despite their hereditary origin, diseases such as sickle cell anemia, polycystic kidney disease, and retinitis pigmentosa, are included in the Rating Schedule and can be service connected if symptoms of these diseases first manifest themselves after entry into service. Such diseases can also be found to have been aggravated by service when there is evidence that there were symptoms of disease prior to entry into service and evidence that there was progression during service at a rate greater than normally expected according to the accepted medical authority.14
Role of C&P Medical Examiners in Evaluating Aggravation of Preservice Disability Claims
As already noted, the general medical examination worksheet directs the examiner in the Veterans Health Administration (VHA) to determine whether an injury or disease occurred before, during, or after active military service and, if before active service, to describe any worsening of the preexisting condition due to being in active service.
When ordering the examination of someone claiming aggravation of a preservice condition, the rater could ask for the examiner’s opinion of whether it is more likely than not that a veteran’s condition existed preservice and was worsened by being on active duty rather than by the natural progression of the condition. Whether and how often this is done is not known.
In addition, according to VHA policy,
Veteran patients may request descriptive statements regarding their medical conditions and/or opinions concerning the “possible cause(s)” of an existing medical condition for VA disability claims purposes. VHA health-care providers shall provide a statement or opinion describing a patient’s medical condition. If the health-care provider is the veteran’s treating physician, and is unable, or deems it inappropriate, to provide an opinion or statement, such physician shall refer the veteran’s request to another health-care provider for the opinion or statement (VHA, 2000).
COMPENSATION FOR SECONDARY SERVICE CONNECTION AND FOR SECONDARY SERVICE CONNECTION BY AGGRAVATION
As the title of the regulation suggests, there are two categories of claims that can be granted secondary service connection under VA regulation 3.310, “Disabilities that are proximately due to, or aggravated by, service-connected disease or injury.”
The first category includes claims for which there is an initial service-connected disability, and then a subsequent disability or disabilities found to be proximately due to (caused by) the service-connected disability. One example of this type of claim would be loss of limb due to amputation occurring subsequent to a service-connected diabetes diagnosis.15 The loss of a limb, it might be argued, should be service connected in addition to the diabetes because the amputation may not have been needed had the veteran not developed diabetes.
In the two-year period from October 2004 through September 2006, nearly 260,000 veterans were service connected for conditions proximately due to service-connected disabilities. This accounted for approximately 19 percent of the more than 1.3 million disabilities that were service connected during that period. Most of the disabilities were rated at 10 or 20 percent (Figure 9-2). Less than 10 percent were rated at 50 percent or higher.
Ten conditions (Table 9-2) accounted for 55 percent of the disabilities compensated as secondary to service-connected disabilities in 2005–2006.
In accord with a 1995 court decision (Allen v. Brown, 7 Vet. App. 439), VA will also grant service connection under this regulation in claims where there is an increase in the severity of nonservice-connected disability that is found to be due to aggravation by a service-connected disability. These are called secondary service connection by aggravation claims or, after the
TABLE 9-2 10 Most Common Diagnoses Service Connected as a Secondary Condition, FY 2005–FY 2006
Diagnostic Code |
Disability |
Number of Cases |
8520 |
Sciatic nerve, paralysis |
40,761 |
7522 |
Erectile dysfunction |
24,406 |
8515 |
Median nerve, paralysis |
17,790 |
8521 |
External popliteal nerve |
13,685 |
7005 |
Arteriosclerotic heart disease |
10,188 |
7114 |
Arteriosclerosis obliterans |
8,538 |
7101 |
Hypertensive vascular disease |
7,103 |
7541 |
Renal involvement in systemic diseases |
7,008 |
8620 |
Sciatic nerve, neuritis |
6,476 |
9434 |
Degenerative arthritis of the spine |
5,371 |
SOURCE: Communication from Bradley G. Mayes, director, C&P Service, Department of Veterans Affairs, December 14, 2006. |

FIGURE 9-2 Distribution of grants for secondary service connection by rating degree from 0 to 100 percent, FY 2005–FY 2006.
SOURCE: Communication from Bradley G. Mayes, director, C&P Service, Department of Veterans Affairs, December 14, 2006.
name of the court case, Allen aggravation claims. One example of this type of claim would be a veteran with a service-connected left knee injury who, after service, goes on to develop arthritis in his or her right hip. It could be argued that, through the effects of the knee injury on gait, the hip arthritis is exacerbated to a level beyond what would have been had there not been a service-connected knee injury.
For the period October 2004 through September 2006, approximately 41,000 claims were granted service connection based on aggravation of a nonservice-connected condition by a service-connected condition.16
What Is a Secondary Condition?
Secondary condition is a relatively new term in the disability and public health arenas. It began to be accepted around 1990 as an expansion of the concept of comorbidity, which is used to refer to conditions that exist in a single person simultaneously, but that are not known to be related in any manner (CDC, 2004a). A person having coexisting skin malignancy and hearing loss would be said to have comorbidities, because there is no known relationship between these two conditions.
From a strictly medical perspective, a secondary condition is a condition with its own pathophysiology that is due to, or caused by, the presence of a preceding primary condition. Secondary conditions can be distinguished from secondary manifestations, the latter referring to sequelae or subsequent complications arising from the same underlying pathophysiologic process as the primary condition.
Diabetes is a good example of a condition with many secondary manifestations. Diabetes itself is an abnormal metabolism of glucose (that can be induced in several ways, including trauma), which has an associated abnormality in lipid metabolism, which leads to an accelerated process of arteriosclerosis. This combination leads to a higher frequency and earlier onset of, among other things, peripheral vascular disease, coronary arteriosclerosis, peripheral neuropathy, and premature cataracts of the eyes. These can be considered secondary manifestations because they are expressions of the person’s underlying diabetes and share the same underlying pathophysiology.
At times the Rating Schedule treats what are in fact secondary manifestations as secondary conditions. The instructions on rating diabetes mellitus (diagnostic code 7913 under CFR 4.119 Schedule of ratings—endocrine system), for example, tell raters to evaluate compensable complications of diabetes separately, except in cases where they are a part of a 100 percent
evaluation (diabetes ratings below 100 percent do not take into account compensable complications).
Rating Secondary Service Connection Claims
In a presentation before the committee, C&P Service staff stated that decisions on secondary claims are based on the facts of the individual case and the medical opinion solicited from the VHA examiner on the general medical examination form. Using this evidence, the rater determines whether it is at least as likely as not that each claimed secondary condition was caused by the primary service-connected condition.
The process of assigning ratings in secondary claims is the same as in claims involving multiple individually service-connected conditions. Each condition is first evaluated separately and assigned a percentage rating. Starting with the condition with the highest percentage rating, the rater then uses VA’s combined ratings table to calculate an overall percentage rating for the primary condition and all conditions found to be proximately due to the primary condition.
Cardiovascular Disease
Ischemic or other cardiovascular disease that develops in a veteran with a service-connected amputation of a lower extremity at or above the knee, or service-connected amputations of both lower extremities at or above the ankles, is presumptively secondary to the amputation or amputations.17
Alcohol and Drug Abuse
In some cases there are nonmedical considerations in allowing service connection for secondary conditions. Examples in training materials include alcohol or drug abuse resulting secondarily from a service-connected disorder, such as posttraumatic stress disorder (PTSD). Federal law (38 U.S.C. § 1110) permits a veteran to receive compensation for an alcohol abuse or drug abuse disability acquired as secondary to, or as a symptom of, a veteran’s service-connected disability, although according to the Federal Circuit Court of Appeals, it precludes compensation for secondary disabilities, such as cirrhosis of the liver, that result from primary alcohol abuse (i.e., voluntary and willful drinking to excess during the time of service).18
Rating Secondary Service Connection by Aggravation Claims
Regulation 3.310(b), or aggravation of nonservice-connected disabilities (referred to in our report as Allen aggravation claims) reads as follows:
Any 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. However, VA will not concede that a nonservice-connected disease or injury was aggravated by a service-connected disease or injury unless the baseline level of severity of the nonservice-connected disease or injury is established by medical evidence created before the onset of aggravation or by the earliest medical evidence created at any time between the onset of aggravation and the receipt of medical evidence establishing the current level of severity of the nonservice-connected disease or injury. The rating activity will 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.
According to the Veterans Benefits Administration (VBA) rating manual, the first step in rating Allen aggravation claims is to collect all “potentially relevant” medical records from the veteran’s providers. Once this is complete, the rater requests a medical examination.
The examination is conducted by a VHA physician and includes a review of all records in the claims folder to establish the baseline level of nonservice-connected disability, and the additional level of disability that occurred due to the service-connected disability.
To be considered adequate for rating purposes, the examiner’s report must separately address the following:19
-
the baseline manifestations that are due to the effects of nonservice-connected disease or injury;
-
the increased manifestations that, in the examiner’s opinion, are proximately due to a service-connected disability based on medical considerations; and
-
the medical considerations supporting an opinion that increased manifestations of a nonservice-connected disease or injury are proximately due to a service-connected disability.
An examination that fails to identify baseline findings, or the increment of increased disability due to service-connected causes, should not be considered adequate for rating purposes. In the event that the report does not meet these requirements and also fails to explain why it would be mere speculation to comment on these matters, the rater is instructed to send the report back to the examiner. When the examination report is complete, the rater uses the findings to assign a rating to the claimed conditions.
There are no instructions on how the rater is to use the findings from the examination to adjudicate the claim. However, as is the case in aggravation of preservice disability claims, in Allen aggravation claims there is assessment of whether disability is the result of the service-connected disability (military service, in aggravation of preservice disability claims) or the natural progress of disease, and in both types of claims the veteran is compensated for the degree of disability over and above that existing prior to aggravation. Because of these similarities, the rating process in Allen aggravation claims may be similar to that outlined in the earlier sections of this chapter on aggravation versus natural progress of disease and rating aggravation of preservice disability claims. However, there is one important distinction. In aggravation of preservice disability claims, when the evidence of degree of preservice disability is not available, there is no penalty to the veteran; the veteran receives the overall rating for his or her condition at the time of application with no deduction of the percent of disability existing preservice. In Allen aggravation claims, if there is no medical evidence of the baseline level of severity of the nonservice-connected disability before the onset of aggravation by the service-connected disability, VBA will not consider the claim.
FINDINGS AND RECOMMENDATIONS
Aggravation of Preservice Disability and Allen Aggravation Claims
Aggravation of preservice disability claims involve an assessment of the worsening of a condition existing preservice due to service. Allen aggravation claims involve an assessment of the worsening, due to a service-connected condition, of a nonservice-connected condition that could have developed either before or after service. Regarding aggravation, the statement of task asks the committee to “determine what medical principles and practices should be applied in determining whether a preexisting disease was increased due to military service or was increased due to the natural process of the disease.” The committee interprets this task as referring to aggravation of preservice disability claims and not Allen aggravation claims, and assumes its sponsor either intended for Allen aggravation to be addressed with secondary conditions (since these claims are categorized
under secondary conditions in VA regulations), or omitted it unintentionally from the statement of task. However, insofar as both aggravation of preservice disability and Allen aggravation claims involve an assessment of worsening of disability over and above some previous level, both can be addressed by the committee simultaneously.
When a veteran files an aggravation of preservice disability claim, VA has the burden of proving the veteran was in sound condition on enlistment. If, in this process, it is discovered from medical evidence that there was a condition existing preservice, and that the condition has since increased in severity, VBA must proceed with adjudication of the claim. Raters weigh medical evidence, which may include the opinion of a VHA medical examiner, to determine whether it is at least as likely as not that the preservice disability was aggravated by service rather than increased in severity due to the natural process of the disease.
The adjudication process in Allen aggravation claims is similar. The rater collects medical records and requests a medical examination by a VHA physician, the findings of which are used to document the baseline level of the nonservice-connected disability when it began, and the presence and degree of worsening of the nonservice-connected disability since. If the condition has worsened, the rater must then determine whether the worsening of the nonservice-connected disability is due to the service-connected disability or the natural process of disease.
As is the case in all disability claims, raters who often have no medical training are responsible for reviewing medical evidence and assigning ratings. In aggravation claims, raters have the additional task of deciding whether a condition has worsened and, if it has, whether the worsening is due to the natural process of disease or military service (or, in Allen aggravation claims, whether the worsening is due to the natural process of disease or a nonservice-connected disability).
The committee has learned that, when ordering the examination of someone claiming aggravation of a preservice condition, the rater could ask for the physician’s opinion of whether it is more likely than not that the condition existed preservice and was worsened by being on active duty rather than by the natural progression of the condition. For all types of claims, VHA policy also allows veterans to request descriptive statements regarding the possible causes of their conditions from VHA examiners. However, how often either is done is not known.
Recommendation 9-1. VA should seek the judgment of qualified experts, supported by findings from current peer-reviewed literature, as guidance for adjudicating both aggravation of preservice disability and Allen aggravation claims. Judgment could be provided by VHA examiners, perhaps from VA centers of excellence, who have the appro-
priate expertise for evaluating the condition(s) in question in individual claims.
Secondary Service Connection
The statement of task asks the committee to “determine what medical principles and practices should be applied in determining whether a causal relationship exists between two conditions.” Currently, raters consult medical records to determine whether it is at least as likely as not that a claimed secondary condition was caused by a service-connected condition.
Causation
In epidemiology, well-established criteria are used to aid in judging the strength of the relationship between two variables at the population level. Perhaps the best known are those that were set forth in the U.S. Surgeon General’s 1964 report on the relationship between smoking and health (CDC, 1964). These include the following:
-
Temporal relationship—relationship in time between two variables; an exposure cannot be considered a cause of an outcome unless it can be shown to have preceded the outcome in time
-
Consistency—replication of research findings on the relationship between a given exposure and an outcome, especially across study designs and populations
-
Strength of association—degree of association between two variables as measured statistically; the greater the association, the more likely the causal role of the exposure
-
Specificity—degree to which the occurrence of the outcome depends on the presence of the exposure; if the outcome is known to occur in relation to exposures other than the one in question, then the relationship is considered less specific
-
Biological plausibility—known biological mechanism by which a certain exposure might increase or decrease likelihood of the outcome
Using such criteria, evidence classification schemes can be developed. In the U.S. Surgeon General’s 2004 report (CDC, 2004b) on the health consequences of smoking, for example, conclusions concerning the evidence that smoking causes health outcomes such as cancer and cardiovascular disease were placed into one of the following four categories:
-
sufficient to infer a causal relationship
-
suggestive but not sufficient to infer a causal relationship
-
inadequate to infer the presence or absence of a causal relationship
-
suggestive of no causal relationship
In VA’s case, raters and examiners are dealing with determining causation at the individual level, where the primary service-connected condition is the exposure and the claimed secondary condition is the outcome. Where research is available, VA could use epidemiologic criteria for causation and evidence classification schemes to inform decision-making on secondary claims. The committee is aware that this might require regulatory action to implement.
Recommendation 9-2. VA should guide clinical evaluation and rating of claims for secondary service connection by adopting specific criteria for determining causation, such as those cited above (e.g., temporal relationship, consistency of research findings, strength of association, specificity, plausible biological mechanism). VA should also provide and regularly update information to compensation and pension examiners about the findings of epidemiological, biostatistical, and disease mechanism research concerning the secondary consequences of disabilities prevalent among veterans.
REFERENCES
ADA (American Diabetes Association). 2007. Complications of diabetes in the United States. http://www.diabetes.org/diabetes-statistics/complications.jsp (accessed May 23, 2007).
CDC (Centers for Disease Control). 1964. Smoking and health: Report of the Advisory Committee to the Surgeon General of the Public Health Service. PHS Publication No. 1103. Washington, DC: CDC.
CDC (Centers for Disease Control and Prevention). 2004a. Children and adults with disabilities: Secondary conditions. http://0-www.cdc.gov.mill1.sjlibrary.org/NCBDDD/factsheets/DH_sec_cond.pdf (accessed December 5, 2006).
CDC. 2004b. The health consequences of smoking: A report of the Surgeon General. Atlanta, GA: CDC. http://www.cdc.gov/tobacco/data_statistics/sgr/sgr_2004/chapters.htm (accessed April 3, 2007).
VHA (Veterans Health Administration). 2000. VHA Directive 2000-029, provision of medical opinions by VA health care practitioners. http://www.va.gov/vhapublications/ViewPublication.asp?pub_ID=74 (accessed December 20, 2006).
VA (Department of Veterans Affairs). 2005. Instructor guide: General policy in rating. Washington, DC: VA.