Citation Nr: 9908083 Decision Date: 03/25/99 Archive Date: 03/31/99 DOCKET NO. 96-27 745 ) DATE ) ) On appeal from the Department of Veterans Affairs Regional Office in Columbia, South Carolina THE ISSUE Entitlement to service connection for the cause of the veteran's death. REPRESENTATION Appellant represented by: The American Legion WITNESS AT HEARING ON APPEAL Appellant's mother ATTORNEY FOR THE BOARD Phillip L. Krejci, Associate Counsel INTRODUCTION The veteran had active service from February 1967 to December 1970. He died in December 1995 and the appellant is his daughter. The appeal arises from a March 1996 rating decision of the Columbia, South Carolina, Regional Office (RO) which denied service connection for the cause of the veteran's death. On an April 1993 statement, the veteran filed a claim for service connection for peripheral neuropathy secondary to Agent Orange exposure. The claim was denied in an April 1994 rating decision. There followed a November 1994 Notice of Disagreement, a January 1995 Statement of the Case, and a January 1995 Substantive Appeal wherein the veteran requested a hearing at the RO. In a May 1995 letter, the veteran asked that the hearing be postponed to enable him to obtain additional medical evidence. In an August 1995 letter, his representative reported that the veteran had been unable to find favorable medical evidence and asked that the hearing be scheduled. The veteran died before the hearing was convened. The veteran's daughter filed a March 1996 Application for Dependency and Indemnity Compensation, Death Pension and Accrued Benefits by a Surviving Spouse or Child (Including Death Compensation If Applicable), VA Form 21-534. A claim for dependency and indemnity compensation includes a claim for death pension and, by the express language of Form 21- 534, also includes a claim for accrued benefits. See Isenhart v. Derwinski, 3 Vet.App. 177 (1992). The March 1996 rating decision did not address death pension or accrued benefits, and these issues are therefore referred to the RO for appropriate action including, if warranted, notification to the appellant of the information needed to complete the application. 38 U.S.C.A. § 5103(a); Isenhart, supra; see also Jones v. West, 136 F.3d 1296 (Fed. Cir. 1998) (where veteran had claim pending at date of death, eligible survivor may file for accrued benefits). FINDINGS OF FACT 1. All available relevant evidence necessary for an equitable disposition of the veteran's appeal has been obtained by the RO. 2. The veteran died in December 1995 at age 53, and an autopsy was performed. The immediate cause of death was listed as sepsis due to, or as a consequence of, thrombotic thrombocytopenia purpura. Sinusitis, seizures, and subdural hematoma were other significant conditions contributing to death but not resulting in the underlying cause. 3. At the time of the veteran's death, service connection was in effect for recurrent dislocation of the left shoulder. There were no other service-connected disabilities. 4. The veteran was first diagnosed with autoimmune thrombocytopenic purpura many years after military service and neither that disorder, nor sepsis, thrombotic thrombocytopenic purpura, sinusitis, seizures, or subdural hematoma, is attributable to such service. CONCLUSIONS OF LAW 1. A service-connected disability did not cause, or contribute substantially or materially to cause, the veteran's death. 38 U.S.C.A. §§ 1310, 5107(West 1991); 38 C.F.R. § 3.312 (1997). 2. Sepsis, thrombotic thrombocytopenia purpura, sinusitis, seizures, subdural hematoma, and autoimmune thrombocytopenic purpura were not incurred in, or as a result of military service. 38 U.S.C.A. §§ 1110, 1116, 5107 (West 1991); 38 C.F.R. §§ 3.303(a), 3.307(a)(6), 3.309(e) (1997). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS Background and Evidence The veteran died on December [redacted], 1995, and the February 1996 death certificate listed the immediate cause of death as sepsis due to, or as a consequence of, thrombotic thrombocytopenia purpura. Sinusitis, seizures, and subdural hematoma were listed as other significant conditions contributing to death but not resulting in the underlying cause. Autopsy findings were reported as consistent with thrombotic thrombocytopenic purpura. The veteran's service medical records are negative for any disorder cited on the death certificate as an immediate, underlying, or contributory, cause of the veteran's death. However, service medical records reflect numerous entries relative to a left shoulder disorder, and he was granted service connection for recurrent left shoulder dislocation in a February 1985 rating decision. A 20 percent disability rating was assigned. Records from Spartanburg General Hospital show that the veteran was admitted in January 1984 with a large hematoma on the right buccal mucosa, other small hematomas in and around the mouth, and petechiae over the lower extremities. Laboratory studies showed hemoglobin of 11.90, hematocrit of 35.7 percent, and a platelet count of 7,300. Bone marrow aspiration revealed erythroid hyperplasia with increased storage of iron and megakaryocytes. The diagnosis was autoimmune thrombocytopenic purpura. He failed to respond to steroid therapy, so his spleen was removed and, at the time of discharge in February 1984, his platelet count was up to 339,000. At an October 1985 VA hearing, the veteran testified that, while in Vietnam, he was an infantry platoon leader and patrolled in areas that were chemically defoliated. On one occasion, his patrol encountered land leeches and they returned to their firebase to remove them. However, he missed a leech, felt a pain, discovered the leech and killed it. Prior to the splenectomy, he noticed small hematomas in his mouth but, on a Saturday night in January 1984, he found a large one on one cheek and more on the other cheek the next day. He went to the hospital emergency room and the first thing he was asked was whether he had been exposed to any chemicals. He immediately thought of Agent Orange exposure in service. He was admitted and had the splenectomy several days later. Between his 1970 separation from service and the 1984 splenectomy, he had not had any treatment for skin rashes or any disorder related to chemical exposure. He thought there was a possibility that Agent Orange, or the injury caused by a leech contaminated by Agent Orange, caused the blood disorder which resulted in his January 1984 splenectomy. On a December 1985 VA examination, the veteran complained of itching of both legs and an occasional rash of the hands and feet. He reported service in Vietnam, probable exposure there to Agent Orange, and leech bites. He also reported the January 1984 diagnosis of autoimmune thrombocytopenic purpura, steroid treatment, and splenectomy. On examination of the skin, there was normal turgor, no icterus, and no dermatitis. Platelet count was 319,000. Save for reference to the splenectomy scar, findings on examination did not relate to thrombocytopenic purpura. Diagnoses included postoperative status splenectomy and "[a]utoimmune thrombocytopenic purpura which can be caused by [A]gent [O]range and with high probability due to mechanism of thrombocytosis antibodies sensitized platelets." On a September 1986 VA discharge summary, the veteran reported leech bites and service in chemically defoliated areas of Vietnam. He also reported finding blood blisters in his mouth for several months prior to a January 1984 hospital admission for low platelet count. He was tried on Prednisone for four days, his spleen was removed, his platelet count increased to more than 300,000, and Prednisone was tapered and then discontinued. His platelet count remained in the normal range and he had no bleeding or bruising. He was concerned that his blood disorder was related to Agent Orange exposure or leech bites in service. Extensive laboratory studies revealed hemoglobin of 11.90, hematocrit of 46.3 percent, and a platelet count of 327,000. After examination and laboratory studies, the examiners concluded that the veteran had idiopathic thrombocytopenic purpura (ITP) that responded well to a splenectomy, the condition was under good control, and there was no need for therapy. The report also noted, "In regard to the possibility of his ITP being related to his exposure to defoliant (Agent Orange?) and/or the bites by leeches, this situation is not confirmed, consequently we had to say that at the present time there is no proof that the exposure to Agent Orange and/or the bites by leeches causes ITP." In a decision of July 1988, the Board denied service connection for splenectomy claimed as a result of exposure to Agent Orange. Outpatient treatment records from a private physician, beginning in January 1995, indicate that the veteran's platelet count decreased to 13,000, that gammaglobulin and steroids were administered, and that he responded with an increased platelet count in excess of 300,000. An October 1995 record from Mary Black Memorial Hospital reported that the veteran was admitted for gammaglobulin treatment after his platelet count dropped to 14,000. Diagnoses on admission included severe autoimmune thrombocytopenic purpura, refractory to steroids, status post splenectomy. A November 1995 admission record from Spartanburg Regional Medical Center noted that the veteran had been in excellent health all of his adult life until January 1984, when he presented with a hematoma of the right buccal mucosa which led to a diagnosis of autoimmune mediated thrombocytopenia and a splenectomy. He had responded well to the splenectomy and further therapy was not needed until January 1995 when he again presented with a hematoma of the right buccal mucosa and a dramatically decreased platelet count. Since January 1995, he had two similar episodes of thrombocytopenia with the most recent in October. Currently, he again had a hematoma of the right buccal mucosa and a platelet count of 28,000; he denied hematuria, rectal bleeding, petechiae or hematoma in any other areas. His appetite and energy level were good and he denied fever, chills, fatigue, headaches, visual changes, or changes in overall cognition. On examination, there was a 1 to 2 cm hematoma on the right buccal mucosa and several smaller areas of discoloration, thought to be smaller hematomas, noted on the upper palate. The assessment was autoimmune thrombocytopenia with recurrent episodes of thrombocytopenia responsive to immunoglobulins in the past. The diagnosis on a November 1995 bone marrow study was erythroid hyperplasia with dyserythropoiesis and hypermegakaryocytes--possible myelodysplastic syndromes. A November 1995 outpatient treatment note by his private physician indicated that the veteran was to be discharged from Spartanburg Regional Medical Center and admitted to the University of Alabama hospital. The University of Alabama autopsy report noted that the veteran was admitted on November 22, 1995, with thrombotic thrombocytopenic purpura. His hospital stay was complicated by fever, right hemiparesis, subdural hematomas, seizures, and thrombocytopenia and hemolytic anemia refractory to treatment. The autopsy summary indicated the veteran had died of thrombotic thrombocytopenic purpura and its complications. At a January 1997 VA hearing, the veteran's ex-wife testified that she and the veteran were married from 1975 to 1982 and the appellant is their daughter. She remembered that the veteran was upset because private and VA dermatologists were unable to cure rashes that he had. After he noticed splotches in and around his mouth, his spleen was removed. More recently, he had several transfusions and underwent a procedure to "wash" his blood. She stated that, during his last hospitalization at the University of Alabama, he had not responded to any treatment. Analysis The appellant contends, through her mother, that the RO erred by failing to grant service connection for the cause of the veteran's death. She maintains that her father served in Vietnam and was there exposed to Agent Orange, and that exposure to that chemical caused his death. The spouse, children, and parents of a veteran whose death was caused by a service-connected disability may be entitled to benefits. 38 U.S.C.A. § 1310. Death is deemed to have been caused by a service-connected disability when the evidence establishes that a service-connected disability was either the principal or a contributory cause of death. 38 C.F.R. § 3.312(a). A service-connected disability is deemed to have been the principal cause of death when it, alone or jointly with another disorder, was the underlying cause of death or was etiologically related thereto. 38 C.F.R. § 3.312(b). In determining whether a service- connected disability was a contributory cause of death, it must be shown that a service-connected disability contributed substantially, materially, or combined with another disorder to cause death, or that it aided or lent assistance to the production of death. 38 C.F.R. § 3.312(c). The first question, then, is whether the veteran's death was caused by a disability for which service connection had been granted. In this case, service connection was in effect for recurrent dislocation of the left shoulder. The death certificate listed the immediate cause of death as sepsis due to, or as a consequence of, thrombotic thrombocytopenic purpura with sinusitis, seizures, and subdural hematoma listed as other significant conditions contributing to death but not resulting in the underlying cause. Thus, the veteran's service-connected disability did not cause his death and no evidence has been presented of an etiologic relationship between his recurrent left shoulder dislocations and any disorder that caused or contributed to his death. The next question is whether service connection can be granted for any of those disorders that did cause or contribute to the veteran's death which, according to the death certificate, are sepsis, thrombotic thrombocytopenic purpura, sinusitis, seizures, or subdural hematoma. As to this issue, a threshold consideration must be whether the appellant has presented a well-grounded claim. A well- grounded claim is one which is plausible. If not, the claim must fail and there is no further duty to assist in the development of the claims. 38 U.S.C.A. § 5107; Murphy v. Derwinski, 1 Vet.App. 78 (1990). This requirement has been reaffirmed by the United States Court of Appeals for the Federal Circuit, in its decision in Epps v. Gober, 126 F.3d 1464 (Fed. Cir. 1997), cert. denied sub nom. Epps v. West, 118 S. Ct. 2348 (1998). That decision upheld the earlier decision of the United States Court of Appeals for Veterans Claims (known as the Court of Veterans Appeals prior to March 1, 1999) which made clear that it would be error for the Board to proceed to the merits of a claim which is not well grounded. Epps v. Brown, 9 Vet.App. 341 (1996). The Court of Appeals for Veterans Claims has held that a claim for service connection for cause of death, like a claim for service connection for disability by a living veteran, must be well grounded. Johnson v. Brown, 8 Vet.App. 423, 426 (1995). In order for a claim for service connection to be well grounded, the Court has also held that there must be competent evidence of: (1) a current disability (a medical diagnosis); (2) the incurrence or aggravation of a disease or injury in service (lay or medical evidence); and (3) a nexus (that is, a link or a connection) between the in- service injury or aggravation and the current disability. Competent medical evidence is required to satisfy this third prong. Caluza v. Brown, 7 Vet. App. 498 (1995), aff'd per curiam, 78 F.3d 604 (Fed. Cir. 1996) (table). "Although the claim need not be conclusive, the statute [38 U.S.C.A. § 5107] provides that [the claim] must be accompanied by evidence" in order to be considered well grounded. Tirpak v. Derwinski, 2 Vet.App. 609, 611 (1992). In a claim of service connection, this generally means that evidence must be presented which in some fashion links the current disability to a period of military service or to an already service-connected disability. 38 U.S.C.A. § 1110 (West 1991); 38 C.F.R. § 3.303 (1996); Rabideau v. Derwinski, 2 Vet.App. 141, 143 (1992); Montgomery v. Brown, 4 Vet. App. 343 (1993). Although evidence submitted in support of a claim is generally presumed to be true for purposes of determining whether it is well grounded, lay assertions of medical diagnosis or causation do not constitute competent evidence sufficient to render a claim well grounded. See Grottveit v. Brown, 5 Vet.App. 91, 93 (1993); King v. Brown, 5 Vet.App. 19, 21 (1993); Espiritu v. Derwinski, 2 Vet.App. 492, 495 (1992). In a claim seeking service connection for the cause of death of a veteran, the first requirement of well-groundedness, evidence of a current disability, will always have been met (the current disability being the condition that caused the veteran to die), but the last two requirements must be supported by evidence of record. Ramey v. Brown, 9 Vet.App. 40, 46 (1996), aff'd sub nom. Ramey v. Gober, 120 F.3d 1239 (Fed. Cir. 1997), cert. denied, 118 S. Ct. 1171 (1998). Evidentiary assertions by the claimant must be accepted as true for the purposes of determining whether a claim is well- grounded, except where the evidentiary assertion is inherently incredible or when the fact asserted is beyond the competence of the person making the assertion. King v. Brown, 5 Vet.App. 19, 21 (1993). In order to establish service connection for a disability, there must be objective evidence which establishes that such disability either began in or was aggravated by service. 38 U.S.C.A. § 1110. If a disability is not shown to be chronic during service, service connection may nevertheless be granted when there is continuity of symptomatology post- service. 38 C.F.R. § 3.303(b). Regulations also provide that service connection may be granted for a disease diagnosed after service discharge when all the evidence establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). A determination of service connection requires a finding of the existence of a current disability and a determination of a relationship between that disability and an injury or disease incurred in service. Watson v. Brown, 4 Vet. App. 309, 314 (1993). In addition, certain diseases, when manifested to a degree of 10 percent or more within one year after the veteran's military service ended, may be presumed to have been incurred in service. 38 U.S.C.A. §§ 1101, 1112, 1113; 38 C.F.R. §§ 3.307, 3.309. This presumption is rebuttable by affirmative evidence to the contrary. 38 U.S.C.A. § 1113; 38 C.F.R. § 3.307(d). A chronic, tropical, or prisoner-of-war related disease, or a disease associated with exposure to certain herbicide agents, listed in 38 C.F.R. § 3.309, may be considered to have been incurred in service under certain circumstances, even though there is no evidence of such disease during the period of service. No condition other than one listed in 38 C.F.R. § 3.309(a) will be considered chronic. 38 U.S.C.A. §§ 1101, 1112, 1113, 1116; 38 C.F.R. § 3.307(a). A veteran who, during active military, naval, or air service, served in the Republic of Vietnam during the Vietnam era, and has a disease listed at 38 C.F.R. § 3.309(e), shall be presumed to have been exposed during such service to a herbicide agent, unless there is affirmative evidence to establish that the veteran was not exposed to any such agent during that service. The last date on which such a veteran shall be presumed to have been exposed to a herbicide agent shall be the last date on which he or she served in the Republic of Vietnam during the Vietnam era. "Service in the Republic of Vietnam" includes service in the waters offshore and service in other locations if the conditions of service involved duty or visitation in the Republic of Vietnam. 38 C.F.R. § 3.307(a)(6)(iii). If a veteran was exposed to a herbicide agent during active military, naval, or air service, the following diseases shall be service-connected if the requirements of 38 U.S.C.A. § 1116, 38 C.F.R. § 3.307(a)(6)(iii) are met, even though there is no record of such disease during service, provided further that the rebuttable presumption provisions of 38 U.S.C.A. § 1113; 38 C.F.R. § 3.307(d) are also satisfied: chloracne or other acneform diseases consistent with chloracne, Hodgkin's disease, multiple myeloma, non-Hodgkin's lymphoma, acute and subacute peripheral neuropathy, porphyria cutanea tarda, prostate cancer, respiratory cancers (cancer of the lung, bronchus, larynx, or trachea) and soft-tissue sarcomas (other than osteosarcoma, chondrosarcoma, Kaposi's sarcoma, or mesothelioma). 38 C.F.R. § 3.309(e) (1996). The diseases listed at 38 C.F.R. § 3.309(e) shall have become manifest to a degree of 10 percent or more at any time after service, except that chloracne or other acneform disease consistent with chloracne, porphyria cutanea tarda, and acute and subacute peripheral neuropathy shall have become manifest to a degree of 10 percent or more within a year, and respiratory cancers within 30 years, after the last date on which the veteran was exposed to a herbicide agent during active military, naval, or air service. 38 C.F.R. § 3.307(a)(6)(ii). The regulation, further, specifically defines the term "acute and subacute peripheral neuropathy" to mean a transient neuropathy which appears within weeks or months of exposure to a herbicide agent and resolves within two years of the date of onset. 38 C.F.R. § 3.309(e), Note 2. The Secretary of Veterans Affairs has determined that there is no positive association between exposure to herbicides and any other condition for which the Secretary has not specifically determined that a presumption of service connection is warranted. See Notice, 59 Fed. Reg. 341-346 (1994). See also 61 Fed. Reg. 41,442-41,449, and 61 Fed. Reg. 57586-57589 (1996). Notwithstanding the foregoing presumption provisions, which arose out of the Veteran's Dioxin and Radiation Exposure Compensation Standards Act, Pub. L. No. 98-542, § 5, 98 Stat. 2725, 2727-29 (1984), and the Agent Orange Act of 1991, Pub. L. No. 102-4, § 2, 105 Stat. 11 (1991), the United States Court of Appeals for the Federal Circuit has determined that a claimant is not precluded from establishing service connection with proof of direct causation. Combee v. Brown, 34 F.3d 1039, 1042 (Fed. Cir. 1994); Ramey v. Brown, 9 Vet.App. 40, 44 (1996), aff'd sub nom. Ramey v. Gober, 120 F.3d 1239 (Fed. Cir. 1997), 118 S. Ct. 1171 (1998). See Brock v. Brown, 10 Vet.App. 155, 160-61 (1997). Thus, the presumption is not the sole method for showing causation. However, as noted above, where the issue involves a question of medical diagnosis or causation as presented here, medical evidence which indicates that the claim is plausible is required to set forth a well-grounded claim. Grottveit v. Brown, 5 Vet.App. 91, 93 (1993). Upon careful review of the evidentiary record, the Board finds it is clear that the veteran served in Vietnam. We are aware that, because the veteran did not have one of the diseases listed in the above regulation (except, possibly, for peripheral neuropathy, which did not appear within weeks or months of service), it appears that even the presumption of exposure to Agent Orange or other herbicide may be unavailable to the appellant in this case. See McCartt v. West, ___ Vet.App. ___, No. 97-1831, slip op. at 6-7 (Feb. 8, 1999), where the Court stated that "neither the statutory nor the regulatory presumption will satisfy the incurrence element of Caluza where the veteran has not developed a condition enumerated in either 38 U.S.C. § 1116(a) or 38 C.F.R. § 3.309(e)." The Board notes, however, that VA's Adjudication Procedure Manual, M21-1, at Part VI, para. 7.20b, contains a more liberal interpretation of the presumption of exposure, stating that "unless there is affirmative evidence to the contrary, a veteran who served on active duty in the Republic of Vietnam during the Vietnam era is presumed to have been exposed to a herbicide agent." The Court did not expressly invalidate, or even mention, the manual provision in its McCartt decision; therefore, we will apply that more favorable interpretation to the veteran's case. We find that the veteran is entitled to a presumption of exposure to a herbicide agent in service. However, even presuming herbicide exposure in service, the record on appeal shows that the disorder which caused the veteran's death was first diagnosed in 1984, and he left service in 1970. Therefore, medical nexus evidence is required to establish a well-grounded claim. In this regard, we note the statement by the examiner at the December 1985 VA medical examination, to the effect that autoimmune thrombocytopenic purpura could be caused by Agent Orange. Although that statement was not unequivocal, we are well aware that "[t]he Court's word parsing in some of its medical nexus cases has created an unclear picture for ascertaining what degree of certainty is necessary in a medical opinion in order to establish a plausible medical nexus." Hicks v. West, 12 Vet.App. 86, 91 (1998). Therefore, giving the benefit of the doubt to the appellant, we find that this claim is well grounded. The Board is also satisfied that all relevant evidence has been obtained and that no further assistance is required to comply with 38 U.S.C.A. § 5107(a). The task remaining is to determine whether all the evidence supports the claim or is in relative equipoise, with the appellant prevailing in either event, or whether a fair preponderance of the evidence is against the claim, in which case the claim must be denied. Gilbert v. Derwinski, 1 Vet.App. 49 (1990). Before his death, the veteran claimed that autoimmune thrombocytopenic purpura resulted from exposure to Agent Orange in Vietnam, and the appellant has claimed that Agent Orange exposure resulted in the veteran's death. In this regard, the diagnoses following a December 1985 VA examination included "[a]utoimmune thrombocytopenic purpura which can be caused by [A]gent [O]range and with high probability due to mechanism of thrombocytosis antibodies sensitized platelets." On the face of it, that diagnosis appears to be evidence, though not conclusive evidence, of an etiologic relationship between Agent Orange exposure and auto-immune thrombocytopenic purpura, the precursor to thrombotic thrombocytopenic purpura, the underlying cause of the veteran's death. Thus, the diagnosis warrants scrutiny. First, the Board notes that the phrase used by the doctor, "due to mechanism of thrombocytosis antibodies sensitized platelets," appears to be internally inconsistent. By definition, immune thrombocytopenia is characterized by a decrease in the number of blood platelets due to antiplatelet antibodies. DORLAND'S ILLUSTRATED MEDICAL DICTIONARY 1706 (28th ed. 1994). Indeed, the evidence in this case shows that the veteran suffered a dramatic decrease in platelets each time the disorder flared. Thrombocytosis, however, is defined as an increase in the number of platelets in peripheral blood. DORLAND'S, supra, at 1707. Further, the 1985 examination itself did not include findings relative to thrombocytopenia. The only references to the disorder in the examination report were in history provided by the veteran, and the Court has cautioned that history from a patient does not become medical evidence merely because it is recorded by a medical professional. LeShore v. Brown, 8 Vet.App. 406, 409 (1994). If the examiner intended only to assert an etiological relationship between thrombocytopenia and Agent Orange exposure, he did not cite any basis for that assertion. Since the disorders listed in 38 C.F.R. § 3.309(e) were found to have a causal or statistical relationship to Agent Orange exposure, and thrombocytopenia was not included in the list, it appears that the examiner's assertion of an etiological relationship between thrombocytopenia and Agent Orange exposure, in the absence of any medical basis or data to support the assertion, was pure speculation. Finally, after a September 1986 hospitalization and extensive laboratory studies, VA examiners concluded that the veteran's idiopathic thrombocytopenic purpura responded to a splenectomy and was under good control, and that there was no proof of a relationship between it and exposure to Agent Orange or leech bites. In sum, a single examination in 1985 resulted in a diagnosis which, internal inconsistencies aside, suggested an etiologic relationship between Agent Orange exposure and thrombocytopenia. However, the examination did not include findings relative to the disorder, did not refer to scientific studies to support the diagnosis, and appeared to rely solely on history provided by the veteran. On the other hand, a 1986 hospitalization, with examinations and laboratory studies, resulted in the conclusion that there was no evidence of a relationship between Agent Orange exposure and thrombocytopenia. In addition, scientific studies to determine the residuals of Agent Orange exposure have not corroborated the etiologic relationship asserted in the 1985 examination. Clearly, this matter involves a medical question, and the Board is not permitted to draw inferences as to medical causation or etiology without a solid foundation in the record. See Colvin v. Derwinski, 1 Vet.App. 171, 174 (1991). The Court of Appeals for Veterans Claims has held that it is the responsibility of the Board to determine the probative weight to be ascribed as among multiple medical opinions in a case, and to state our reasons or bases for favoring one opinion over another. See Winsett v. West, 11 Vet.App. 420, 424-25 (1998). The Court has also indicated that the probative value of a physician's statement is dependent, in part, upon the extent to which it reflects "clinical data or other rationale to support his opinion." Bloom v. West, ___ Vet.App. ___, No. 97-1463, slip op. at 4 (Feb. 10, 1999). For the reasons discussed above, we conclude that the report of the 1986 VA hospitalization, with its comprehensive tests and studies, must be accorded the greater evidentiary weight in this case. That report indicated that there was no evidence of a relationship between Agent Orange exposure and thrombocytopenia. The Board therefore finds that the preponderance of the evidence in this case is against service connection for the cause of the veteran's death. ORDER Entitlement to service connection for the cause of the veteran's death is denied. ANDREW J. MULLEN Member, Board of Veterans' Appeals