Citation Nr: 21023108 Decision Date: 04/20/21 Archive Date: 04/20/21 DOCKET NO. 16-17 506 DATE: April 20, 2021 ISSUES Entitlement to service connection for sleep disability, to include obstructive sleep apnea (OSA), claimed as due to service-connected posttraumatic stress disorder (PTSD). Entitlement to service connection for gastroesophageal reflux disease (GERD), claimed as due to service-connected PTSD. ORDER Entitlement to service connection for sleep disability, to include obstructive sleep apnea (OSA), claimed as due to service-connected posttraumatic stress disorder (PTSD) is denied. Entitlement to service connection for gastroesophageal reflux disease (GERD), claimed as due to service-connected PTSD is denied. FINDINGS OF FACT 1. A sleep disability, to include obstructive sleep apnea (OSA), was not manifest during active service, or until many years after service, and is not shown to be causally or etiologically related to an in-service event, injury, or disease. 2. A sleep disability, to include obstructive sleep apnea (OSA), was not caused or aggravated by the Veteran’s service-connected PTSD. 3. GERD was not manifest during active service, or until many years after service, and is not shown to be causally or etiologically related to an in-service event, injury, or disease. 4. GERD was not caused or aggravated by the Veteran’s service-connected PTSD. CONCLUSIONS OF LAW 1. A sleep disability, to include obstructive sleep apnea (OSA), was not incurred in or aggravated during service and is not proximately due to, the result of, or aggravated by a service-connected disease or injury. 38 U.S.C. §§ 1110, 1113, 5107; 38 C.F.R. §§ 3.303, 3.310. 2. GERD was not incurred in or aggravated during service and is not proximately due to, the result of, or aggravated by a service-connected disease or injury. 38 U.S.C. §§ 1110, 1113, 5107; 38 C.F.R. §§ 3.303, 3.310. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty in the United States Army from August 1990 to June 1991, and from June 1992 to July 1994, including service in Southwest Asia from September 1990 to May 1991. This matter comes before the Board of Veterans' Appeals (Board) on appeal from a November 2014 rating decision of the Department of Veterans Affairs (VA) Regional Office (RO). The Board notes that on his April 2016 substantive appeal (VA form 9), the Veteran requested a hearing. He subsequently withdrew his request for a hearing in a January 2018 letter; the Board considers his request withdrawn and will proceed. By way of background the Veteran previously filed a claim for service connection for a sleep disability which was denied in a July 2012 rating decision. The Veteran did not appeal that decision and it became final. In April 2014, the Veteran filed to reopen the previously denied claim and also filed a new claim for entitlement to service connection for GERD. Both claims were denied in the November 2014 rating decision on appeal. In February 2020 the Board determined that new and material evidence had been received and reopened the Veteran’s claim for entitlement to service connection for a sleep disability. The Board then remanded the issues in a February 2020 decision/remand for further development. Upon review of the Veteran’s claim file, the Board finds that there has been substantial compliance with the Board's remand directives. See Stegall v. West, 11 Vet. App. 268, 271 (1998); Barr v. Nicholson, 21 Vet. App. 303, 307 (2007). Therefore, the Board will proceed to the merits of the issues on appeal. Service Connection Generally, service connection for a disability requires evidence of: (1) the existence of a current disability; (2) the existence of the disease or injury in service, and; (3) a relationship or nexus between the current disability and any injury or disease during service. Shedden v. Principi, 381 F.3d 1163 (Fed. Cir. 2004). Service connection may also be granted for any injury or disease diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disease or injury was incurred in service. 38 C.F.R. § 3.303 (d). Further, service connection may be warranted for disability that is proximately due to or the result of a service-connected disability. 38 C.F.R. § 3.310 (a). Secondary service connection requires (1) evidence of a current disability; (2) evidence of a service-connected disability; and (3) medical nexus evidence establishing a connection between the service-connected disability and the current disability. Wallin v. West, 11 Vet. App. 509, 512 (1998). A disability deemed proximately due to or the result of a service-connected disease or injury shall be service connected ("secondary service connection"). 38 C.F.R. § 3.310 (a). 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. 38 C.F.R. § 3.310 (b). Under 38 C.F.R. § 3.317, there are two types of qualifying chronic disabilities: (1) An undiagnosed illness; and (2) a medically unexplained chronic multisymptom illness that is defined by a cluster of signs or symptoms, such as: (1) chronic fatigue syndrome, (2) fibromyalgia, and (3) functional gastrointestinal disorders. An undiagnosed illness is defined as a condition that by history, physical examination and laboratory tests cannot be attributed to a known clinical diagnosis. In the case of claims based on undiagnosed illness under 38 U.S.C. § 1117; 38 C.F.R. § 3.317, unlike those for "direct service connection," there is no requirement that there be competent evidence of a nexus between the claimed illness and service. Gutierrez v. Principi, 19 Vet. App. 3, 9 (2004). Further, lay persons are competent to report objective signs of illness. Id. To determine whether the undiagnosed illness is manifested to a degree of 10 percent or more the condition must be rated by analogy to a disease or injury in which the functions affected, anatomical location or symptomatology are similar. 38 C.F.R. § 3.317 (a)(5); see also Stankevich v. Nicholson, 19 Vet. App. 470 (2006). A medically unexplained chronic multisymptom illnesses is one defined by a cluster of signs or symptoms and specifically includes chronic fatigue syndrome, fibromyalgia, and functional gastrointestinal disorders (excluding structural gastrointestinal diseases), as well as any other illness that the Secretary determines meets the criteria in paragraph (a)(2)(ii) of this section for a medically unexplained chronic multisymptom illness. A "medically unexplained chronic multisymptom illness" means a diagnosed illness without conclusive pathophysiology or etiology that is characterized by overlapping symptoms and signs and has features such as fatigue, pain, disability out of proportion to physical findings, and inconsistent demonstration of laboratory abnormalities. Chronic multisymptom illnesses of partially understood etiology and pathophysiology will not be considered medically unexplained. 38 C.F.R. § 3.317 (a)(2)(ii). "Objective indications of chronic disability" include both signs, in the medical sense of objective evidence perceptible to an examining physician, and other, non-medical indicators that are capable of independent verification. 38 C.F.R. § 3.317 (a)(3). Signs or symptoms that may be manifestations of undiagnosed illness or medically unexplained chronic multisymptom illness include, but are not limited to, the following: (1) fatigue; (2) signs or symptoms involving skin; (3) headache; (4) muscle pain; (5) joint pain; (6) neurologic signs or symptoms; (7) neuro-psychological signs or symptoms; (8) signs or symptoms involving the respiratory system (upper or lower); (9) sleep disturbances; (10) gastrointestinal signs or symptoms; (11) cardiovascular signs or symptoms; (12) abnormal weight loss; and (13) menstrual disorders. 38 C.F.R. § 3.317 (b). For purposes of section 3.317, disabilities that have existed for six months or more and disabilities that exhibit intermittent episodes of improvement and worsening over a six-month period will be considered chronic. The six-month period of chronicity will be measured from the earliest date on which the pertinent evidence establishes that the signs or symptoms of the disability first became manifest. 38 C.F.R. § 3.317 (a)(4). Notwithstanding the foregoing presumptive provisions, the Veteran is not precluded from establishing service connection for a disease averred to be related to Gulf War service, as long as there is proof of such direct causation. See generally Combee v. Brown, 34 F.3d 1039, 1043-1044 (Fed. Cir. 1994). Except as otherwise provided by law, a claimant has the responsibility to present and support a claim for benefits under laws administered by the Secretary. The Secretary shall consider all information and lay and medical evidence of record in a case before the Secretary with respect to benefits under laws administered by the Secretary. When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the Secretary shall give the benefit of the doubt to the claimant. 38 U.S.C. § 5107; see also Gilbert v. Derwinski, 1 Vet. App. 49, 53 (1990). To deny a claim on its merits, the evidence must preponderate against the claim. Alemany v. Brown, 9 Vet. App. 518, 519 (1996), citing Gilbert, 1 Vet. App. at 54. In this case, the Board has reviewed all of the evidence of record, with an emphasis on the evidence relevant to this appeal. Although the Board has an obligation to provide reasons and bases supporting its decision, there is no need to discuss, in detail, every piece of evidence of record. Gonzales v. West, 218 F.3d 1378, 1380-81 (Fed. Cir. 2000) (holding that VA must review the entire record but does not have to discuss each piece of evidence). Hence, the Board will summarize the relevant evidence where appropriate and the Board's analysis below will focus specifically on what the evidence shows, or fails to show, with regard to the Veteran's claims. 1. Entitlement to service connection for sleep disability, to include obstructive sleep apnea (OSA), claimed as due to service-connected posttraumatic stress disorder (PTSD). The Veteran is claiming service connection for a sleep disability, to include as secondary to his service-connected PTSD. The Veteran was granted service connection for his PTSD effective October 1996. The Veteran also contends that his sleep disability is the result of his exposure to environmental factors during his service in Southwest Asia. The Veteran's service treatment records contain a July 1994 evaluation in which the Veteran was diagnosed with major depression with moderate PTSD features. The examiner noted that prominent features of this diagnosis are the inability to sleep more than three hours per night with frequent waking. The Board also notes that the Veteran’s July 1994 separation examination does note that the Veteran made complaints of frequent trouble sleeping. The Veteran’s VA and private treatment records reflect that he has made several complaints about insomnia and trouble sleeping over the course of the appeal period. The Veteran was afforded a Persian Gulf Registry examination in November 1996. At that time the Veteran reported low energy and feeling tired all of the time. He reported that he had difficulty falling and staying asleep. The examiner’s impression was a diagnosis of posttraumatic stress disorder and depression. VA provided the Veteran with a Gulf War General Medical Examination for Chronic Fatigue Syndrome in June 2012. At that time the examiner noted that the Veteran did not have a diagnosis of chronic fatigue syndrome. The examiner explained that following a physical examination and labs of the Veteran there was no organic disability shown that would cause fatigue. The Veteran reported only being able to sleep four hours total at night, difficulty falling asleep and more frequent snoring. The examiner opined that the Veteran’s fatigue was due to severe insomnia, and there was no evidence of any “undiagnosed illness”. The examiner also opined that it was less likely than not that the Veteran’s condition was related to service. VA treatment records reflect following a sleep study in January 2014 the Veteran was diagnosed with obstructive sleep apnea. The Veteran was prescribed a continuous positive airway pressure (CPAP) machine for relief. The Veteran was afforded another VA Gulf War General Medical Examination and Disability Benefits Questionnaire (DBQ) was completed in February 2016. Upon review of the Veteran’s claim file the examiner noted that there was no diagnosed illness for which no etiology was established. The examiner noted that the Veteran had a diagnosis of obstructive sleep apnea. The examiner opined that the Veteran’s OSA was less likely than not incurred in or caused by his service. In providing a rationale the examiner explained that OSA is a mechanical condition of the upper airway and no relationship to Gulf War exposures is known or suggested. The examiner also opined that the Veteran’s OSA is less likely than not secondary to or aggravated by the Veteran’s PTSD. The examiner explained that OSA is unrelated to mental health/PTSD conditions. The examiner also stated that insomnia related to PTSD is unrelated to OSA. In the February 2020 remand the Board found the examiner’s opinion on secondary service connection to be inadequate as the examiner provided insufficient rationale to support his negative opinion. The Board also noted that the examiner failed to consider the Veteran’s complaints of frequent trouble sleeping in his July 1994 separation examination. As such, the Board afforded the opinion of the February 2016 examiner limited probative value and remanded the matter for a new examination to assess the nature and etiology of the Veteran’s sleep disability. The Veteran was afforded the Board-directed VA examination for his sleep disability in March 2020. Upon review of the Veteran’s claim file and examination of the Veteran the examiner noted a diagnosis of obstructive sleep apnea. The examiner noted the Veteran’s reported sleep disturbance in 1994, and the examiner stated that at the examination the Veteran attributed this to his PTSD with nightmares. The Veteran was not taking medication at the time but was continuing to use a CPAP machine. As it relates to direct service connection the examiner opined that the Veteran’s sleep apnea was less likely than not incurred in or caused by an in-service event. In providing a rationale the examiner stated that the records do not support nor suggest undiagnosed sleep apnea during or in proximity to service. The examiner stated that although the Veteran reported some snoring in service, snoring is very common and is not at all synonymous with sleep apnea. The examiner also explained that sleep apnea is a medically diagnosable and medically explained condition which is not due to any occupational or environmental exposure. As it relates to secondary service connection, the examiner opined that it was less likely than not that the Veteran’s OSA was due to or aggravated by his PTSD. The examiner explained that OSA is due to the physical obstruction of the upper airways and PTSD would not be medically expected to result in the collapse of the upper airway. By extension PTSD would not aggravate OSA because it would not cause a more severe narrowing or collapse of airways. The examiner explained that risk factors for the Veteran include that he is a male, advancing in age, body habitus and his morbid obesity. The examiner also cited to and explained that several studies have looked at the question and there is conflicting evidence because some studies have found a higher rate of OSA to be concurrent with PTSD. However, the studies conclude that further study would be needed, and PTSD cannot be said to be causative of OSA. The Board finds the March 2020 VA opinion to be of great probative value. Indeed, the examiner considered the Veteran's contention, the claims file, including his previous complaints of insomnia and trouble sleeping and clinical medical evidence before providing a negative opinion. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 304 (2008) (the probative value of a medical opinion is derived from a factually accurate, fully articulated, and soundly reasoned opinion). A medical examination report must contain not only clear conclusions with supporting data, but also a reasoned medical explanation connecting the two. See Stefl v. Nicholson, 21 Vet. App. 120, 124 (2007). The examiner's negative opinion was supported by a sufficiently clear and well-reasoned medical rationale and was consistent with the verifiable facts regarding the Veteran's contentions. See Bloom v. West, 12 Vet. App. 185, 187 (1999); Hernandez-Toyens v. West, 11 Vet. App. 379, 382 (1998); see also Claiborne v. Nicholson, 19 Vet. App. 181, 186 (2005). For example, the examiner explained that sleep apnea is a medically explained condition which is not caused by any environmental factors, such as Guld War exposure. Furthermore, he explained that as OSA is due to a physical obstruction of upper airways, PTSD would not cause an obstruction nor would it cause more severe narrowing of airways. There is no evidence that the March 2020 VA examiner was not competent or credible, and as the report was based on accurate facts and objective examinations, the Board finds that it is entitled to significant probative weight as to the etiology of the Veteran's OSA. See Nieves-Rodriguez, Id. The Board acknowledges the Veteran's contention in his July 2014 Statement in Support of the Claim that his sleep disability is due to environmental exposures while serving in the Persian Gulf and therefore he has essentially argued that service connection is warranted for a sleep disability under 38 C.F.R. § 3.317. However, the Veteran has a distinct diagnosis of obstructive sleep apnea based on the January 2014 sleep study as well as the opinions of the February 2016 and March 2020 VA examiners. Because the Veteran has a distinct medical diagnosis of sleep apnea, his claimed sleep disability is not an undiagnosed illness or a medically unexplained chronic multisymptom illness. Accordingly, service connection under 38 C.F.R. § 3.317 is not warranted. See 38 C.F.R. § 3.317 (providing that service connection is warranted under this section for a qualifying chronic disability, which means a chronic disability resulting from an undiagnosed illness or a medically unexplained chronic multisymptom illness). The Board recognizes that in January 2015 the Veteran submitted web articles which discuss the association between sleep disorders and PTSD. With regard to medical treatise evidence, the United States Court of Appeals for Veterans Claims (Veterans Court) has held that a medical article or treatise "can provide important support when combined with an opinion of a medical professional" if the medical article or treatise evidence discussed generic relationships with a degree of certainty such that, under the facts of a specific case, there is at least "plausible causality" based upon objective facts rather than on an unsubstantiated lay medical opinion. Sacks v. West, 11 Vet. App. 314 (1998); see also Wallin v. West, 11 Vet. App. 509. In this case, however, the medical treatise evidence submitted by the Veteran is not accompanied by the medical opinion of a medical professional. For these reasons, the Board must find that the medical text evidence does not contain the specificity to constitute competent evidence of the claimed medical nexus. See Sacks, 11 Vet. App. at 317; see Libertine v. Brown, 9 Vet. App. 521, 523 (1996). The Board acknowledges that the Veteran is competent to provide statements as to his beliefs that his OSA is related to service. Barr v. Nicholson, 21 Vet. App. 303, 307-08 (2007). In order for lay evidence to be competent, the individual must have personal knowledge, derived from his/her own senses, of what is being attested; "[c]ompetent testimony is thus limited to that which the witness has actually observed, and is within the realm of his personal knowledge." Layno v. Brown, 6 Vet. App. 465, 471 (1994). Here, the Veteran is competent to provide statements about his symptoms relating to his claimed OSA. However, there is nothing in the record to suggest that the Veteran has the appropriate training, experience, or expertise to render a medical opinion regarding etiology of such a condition of any kind. See 38 C.F.R. § 3.159 (a)(1) (setting forth that competent medical evidence means evidence provided by a person who is qualified through education, training, or experience to offer medical diagnoses, statements, or opinions). While the Veteran is competent to report what he has experienced, he is not competent to ascertain the etiology of any current condition, as the causative factors for such are not readily subject to lay observation. See Layno v. Brown, 6 Vet. App. 465 (1994); Woehlaert v. Nicholson, 21 Vet. App. 456, 462 (2007) (concerning rheumatic fever); see also Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007). Accordingly, his assertions to that effect are of no probative value. There are no competent medical opinions of probative value in favor of a positive nexus to active service from any VA examiner or medical treatment provider from any source. Upon review of the record, the Board concludes that entitlement to service connection for a sleep disability is not warranted, either via direct or secondary service connection. The Board notes a current diagnosis of obstructive sleep apnea, and thus the requirement for a current disability is shown. The Board acknowledges the Veteran's contentions, and the Veteran's post-service statements are noted. However, the record is silent for any diagnosis of a sleep disability until the Veteran was diagnosed with OSA in January 2014, and there is no competent evidence to tie the current assertion to any in-service disease or injury. The Board does recognize that the file contains several complaints from the Veteran of issues with sleeping and insomnia, however the Board also notes that examiners have often attributed these symptoms to being directly related to the Veteran’s PTSD. The Board thus finds the Veteran fails the third prong of the test for entitlement to service connection. See Davidson v. Shinseki, 581 F.3d 1313, 1315-16 (Fed. Cir. 2009); Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004); 38 C.F.R. § 3.303. In summary, the medical evidence in this case outweighs the Veteran's assertions that his OSA is of service origin or was caused or aggravated by his service-connected PTSD. For these reasons, the preponderance of the evidence is against the claim and service connection for a sleep disability, to include OSA is not warranted. As the preponderance of the evidence weighs against the claim, the benefit of the doubt rule is not for application. 38 U.S.C. § 5107(b), 38 C.F.R. § 4.3; see Gilbert v. Derwinski, 1 Vet. App. 49, 55 (1990). 2. Entitlement to service connection for gastroesophageal reflux disease (GERD), claimed as due to service-connected PTSD. The Veteran is claiming service connection for GERD, to include as secondary to his service-connected PTSD. The Veteran also contends that his GERD is the result of his exposure to environmental factors during his service in Southwest Asia. The Veteran's service treatment records are silent for any complaints, treatment or diagnosis of a digestive disorder. The Veteran’s July 1994 separation examination is negative for any complaints of frequent indigestion or stomach, liver or intestinal trouble. VA treatment records reflect that the Veteran has been receiving treatment for his GERD symptoms since October 2012. His treatment plan includes him taking Pantoprazole daily for this condition. The Veteran was afforded VA Gulf War General Medical Examination and Disability Benefits Questionnaire (DBQ) was completed in February 2016. The examiner noted that the Veteran had diagnoses of GERD and hiatal hernia. The examiner noted that there were no diagnosed conditions for which no etiology was established. The examiner noted that the Veteran had several risk factors for GERD including obesity, COPD/asthma and tobacco and marijuana use. As it relates to direct service connection the examiner opined that the Veteran’s GERD was less likely than not related to his claimed exposure in the Gulf War. The examiner explained that the Veteran’s GERD was mild and although stress may increase stomach acid, this does not cause GERD. The examiner also stated that the GERD is not noted as a likely result of Gulf War environmental exposure, and also the Veteran’s exposure was 20 years prior to his diagnosis of GERD. The examiner ultimately concluded that the Veteran’s GERD was not “significantly” aggravated by his PTSD. In the February 2020 remand the Board found the examiner’s opinion on secondary service connection to be inadequate, because although the examiner determined that GERD was not “significantly” aggravated by PTSD, the examiner did discuss in his rationale the fact that stress may increase stomach acid when aggravated. As such, the Board afforded the opinion of the February 2016 examiner limited probative value and remanded the matter for a new examination to assess the nature and etiology of the Veteran’s GERD. The Veteran was afforded a new VA examination in March 2020. Upon review of the claims file and an in- person examination of the Veteran the examiner continued the previous diagnosis of GERD. The Veteran reported that he continues to take medication for his condition and suffers from reflux. The Veteran reported that he has not had any weight loss but rather weight gain. In addressing direct service connection, the examiner opined that it was less likely than not that the Veteran’s GERD was incurred in or caused by his Gulf War service. The examiner explained that a review of the records does not support or suggest that GERD occurred during or in proximity to service. GERD is a medically diagnosable and explained condition and is not consistent with any occupational or environmental exposures. The examiner further stated that GERD is not consistent with Gulf War syndrome. As it relates to secondary service connection the examiner opined that GERD was not caused by or further impaired by the Veteran’s PTSD. In providing a rationale the examiner explained that GERD is the result of a lower esophageal sphincter impairment which allows gastric contents to rise into the esophagus and not the result of increased acid production in the stomach. The examiner stated that PTSD would not be causative for this sphincter impairment. Furthermore, the examiner explained that PTSD would not cause further impairment of this esophagal sphincter, leading to aggravation of GERD. The examiner stated that the Veteran is morbidly obese which is a risk factor for GERD and is consistent with the Veteran’s statements that his GERD is getting worse with continued weight gain. The Board finds the March 2020 VA opinion to be of great probative value. Indeed, the examiner considered the Veteran's contention, the claims file, and clinical medical evidence before providing a negative opinion. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 304 (2008) (the probative value of a medical opinion is derived from a factually accurate, fully articulated, and soundly reasoned opinion). A medical examination report must contain not only clear conclusions with supporting data, but also a reasoned medical explanation connecting the two. See Stefl v. Nicholson, 21 Vet. App. 120, 124 (2007). The examiner's negative opinion was supported by a sufficiently clear and well-reasoned medical rationale and was consistent with the verifiable facts regarding the Veteran's contentions. See Bloom v. West, 12 Vet. App. 185, 187 (1999); Hernandez-Toyens v. West, 11 Vet. App. 379, 382 (1998); see also Claiborne v. Nicholson, 19 Vet. App. 181, 186 (2005). For example, the examiner explained that GERD is a medically explained condition which is not caused by any environmental factors such as Gulf War expsoure. Furthermore, he explained that GERD is the result of a lower esophageal sphincter impairment and PTSD would not medically cause or aggravate a sphincter impairment. There is no evidence that the March 2020 VA examiner was not competent or credible, and as the report was based on accurate facts and objective examinations, the Board finds that it is entitled to significant probative weight as to the etiology of the Veteran's GERD. See Nieves-Rodriguez, Id. The Board acknowledges that in his July 2014 Statement in Support of the Claim the Veteran claimed that his GERD is due to environmental exposures while serving in the Persian Gulf and therefore he has essentially argued that service connection is warranted for a GERD under 38 C.F.R. § 3.317. However, a recent case from the United States Court of Appeals for Veterans Claims (CAVC) concludes that GERD is not eligible for presumptive service connection as a medically unexplained chronic multisymptom illness under 38 C.F.R. § 3.317. Atencio v. O'Rourke, 30 Vet. App. 74 (2018). Therefore, GERD does not fall within one of the presumptive diseases under 38 C.F.R. § 3.317. Because the Veteran has a known diagnosis of GERD which is not a condition for which the Secretary has determined a presumption of service connection is warranted under 38 C.F.R. § 3.317 (c), service connection for GERD as a result of an undiagnosed illness or a medically unexplained chronic multisymptom illness is not warranted. The Board acknowledges that the Veteran is competent to provide statements as to his beliefs that his GERD is related to service. Barr v. Nicholson, 21 Vet. App. 303, 307-08 (2007). In order for lay evidence to be competent, the individual must have personal knowledge, derived from his/her own senses, of what is being attested; "[c]ompetent testimony is thus limited to that which the witness has actually observed, and is within the realm of his personal knowledge." Layno v. Brown, 6 Vet. App. 465, 471 (1994). Here, the Veteran is competent to provide statements about his symptoms relating to his claimed GERD. However, there is nothing in the record to suggest that the Veteran has the appropriate training, experience, or expertise to render a medical opinion regarding etiology of such a condition of any kind. See 38 C.F.R. § 3.159 (a)(1) (setting forth that competent medical evidence means evidence provided by a person who is qualified through education, training, or experience to offer medical diagnoses, statements, or opinions). While the Veteran is competent to report what he has experienced, he is not competent to ascertain the etiology of any current condition, as the causative factors for such are not readily subject to lay observation. See Layno v. Brown, 6 Vet. App. 465 (1994); Woehlaert v. Nicholson, 21 Vet. App. 456, 462 (2007) (concerning rheumatic fever); see also Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007). Accordingly, his assertions to that effect are of no probative value. In addition, the Board finds that the gap in time between the Veteran's last date of active service, in July 1994, to his initial evaluation by any medical provider regarding his GERD in October 2012 to be probative of a lack of nexus between the diagnosed current disability and active service. A negative inference may be drawn from the absence of complaints or treatment for an extended period. See Maxson v. West, 12 Vet. App. 453, 459 (1999), aff'd sub nom. Maxson v. Gober, 230 F.3d 1330, 1333 (Fed. Cir. 2000). There are no competent medical opinions of probative value in favor of a positive nexus to active service from any VA examiner or medical treatment provider from any source. Upon review of the record, the Board concludes that entitlement to service connection for GERD is not warranted, either via direct or secondary service connection. The Board notes a current diagnosis of GERD, and thus the requirement for a current disability is shown. The Board acknowledges the Veteran's contentions, and the Veteran's post-service statements are noted. However, the record is silent for mention of GERD until the Veteran began to receive treatment in October 2012, and there is no competent evidence to tie the current assertion to any in-service disease or injury. The Board thus finds the Veteran fails the third prong of the test for entitlement to service connection. See Davidson v. Shinseki, 581 F.3d 1313, 1315-16 (Fed. Cir. 2009); Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004); 38 C.F.R. § 3.303. (Continued on next page.) In summary, the medical evidence in this case outweighs the Veteran's assertions that his current GERD is of service origin or was caused or aggravated by his service-connected PTSD. For these reasons, the preponderance of the evidence is against the claim and service connection for GERD is not warranted. As the preponderance of the evidence weighs against the claim, the benefit of the doubt rule is not for application. 38 U.S.C. § 5107(b), 38 C.F.R. § 4.3; see Gilbert v. Derwinski, 1 Vet. App. 49, 55 (1990). Michael A. Pappas Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board T. Nettey, Associate Counsel The Board’s decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.