Citation Nr: 21061920 Decision Date: 10/05/21 Archive Date: 10/05/21 DOCKET NO. 10-08 365 DATE: October 5, 2021 ORDER Service connection for obstructive sleep apnea (OSA) is denied. Service connection for a left shoulder disability is denied. REMANDED Entitlement to service connection for a back disability is remanded. FINDINGS OF FACT 1. The Veteran's OSA is not linked to disease or injury incurred or aggravated in active service, and has not been caused or aggravated by a service-connected disability. 2. The Veteran's left shoulder disability is not linked to disease or injury incurred or aggravated in active service, and has not been caused or aggravated by a service-connected disability. CONCLUSIONS OF LAW 1. The criteria for service connection for OSA have not been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.310. 2. The criteria for service connection for a left shoulder disability have not been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.310. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from July 1967 to April 1971. These matters come before the Board of Veterans' Appeals (Board) on appeal from a May 2009 rating decision of a Department of Veterans Affairs (VA) Regional Office (RO). The Board remanded the matters for further development in October 2017, October 2019, December 2020, and April 2021. Service Connection Service connection generally will be awarded when a veteran has a disability resulting from disease or injury incurred in or aggravated by active service. 38 U.S.C. § § 1110, 1131; 38 C.F.R. § 3.303(a). Service connection may be granted for any disease diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). To establish service connection on a direct basis, the evidence must show: (1) a current disability; (2) incurrence or aggravation of a disease or injury in service; and (3) a link between the current disability and the disease or injury incurred or aggravated in service (the "nexus" element). Holton v. Shinseki, 557 F.3d 1363, 1366 (Fed. Cir. 2009). Service connection may be granted on a secondary basis for a disability which is proximately due to, or the result of, a service-connected disease or injury. 38 C.F.R. § 3.310(a). Secondary service connection may also be granted for aggravation of a disease or injury by a service-connected disability. 38 C.F.R. § 3.310(b). A claimant is entitled to the benefit of the doubt when there is an approximate balance of positive and negative evidence on any issue material to the claim. 38 U.S.C. § 5107; 38 C.F.R. § 3.102; see Lynch v. McDonough, 999 F.3d 1391, 1395 (Fed. Cir. 2021) (holding that if the positive and negative evidence is in approximate balance, which includes but is not limited to equipoise, the claimant receives the benefit of the doubt). Obstructive Sleep Apnea The Veteran claims service connection for OSA as secondary to his service-connected diabetes mellitus, type II (diabetes). See January 2011 VA Form 21-4138. For the following reasons, the Board finds that service connection is not established. A December 1989 private treatment record reflects that the Veteran underwent a sleep study. He was found to exhibit loud snoring without significant sleep apnea. A February 1990 private electroencephalographic report reflects that the Veteran reported feeling drowsy and tired during the day, and that he had frequent nocturnal awakenings during sleep. A multiple sleep latency EEG was performed with five daytime naps, which was slightly abnormal and suggested daytime hypersomnolence. The Veteran underwent a VA examination in March 2012 as part of the development of this claim to determine whether his OSA may be related to his active service. The examination report reflects that he reported having problems with sleep since the 1980's. He stated that at that time a sleep study was borderline for sleep apnea. He stated he underwent upper airway surgical modification for that reason. In this regard, a separate March 2012 report of a VA examination conducted on the same day assessing his sinusitis notes that the Veteran related he had a deviated septum and enlarged uvula "with swelling and snoring." He stated he had surgery to stop the snoring and decreased oxygenation in 1980. (The Board here notes, and solely for clarification purposes, that the Veteran was apparently relating this history by memory; given the above-discussed sleep study records dated in 1989 and 1990, it seems likely the surgery took place after those studies were performed, and therefore not in 1980 as stated in the examination report.) He stated that over the past ten to fifteen years he had problems with snoring returning, chronic fatigue, and difficulty with "narcolepsy" when driving. He stated he was supposed to have further evaluation with a sleep study. Another VA examination was performed in February 2016. The examination report again notes that the Veteran related he was diagnosed with sleep apnea in 1980. The examiner observed that there was a sleep study done in 1989 (in reference to the study discussed above) that indicated he had loud snoring without significant sleep apnea. The examiner opined that the Veteran's OSA is less likely than not proximately due to or a result of his diabetes. The examiner explained that the two conditions are not medically related. The examiner further stated that OSA is a "separate entity entirely" from diabetes, and that the medical literature did not support a medical relationship. Another VA medical opinion was obtained in November 2017 to address the issue of aggravation. The examiner concluded that the Veteran's sleep apnea was not aggravated beyond its natural progression by diabetes. The examiner explained that nothing in the medical literature shows that diabetes mellitus causes or aggravates OSA. The examiner added that an endocrine condition of the pancreas "could/would not cause or aggravate obstruction of the airway[,] which is diagnostic of OSA." An April 2018 private sleep study reflects that the Veteran had undergone a home sleep study in January 2018 and was diagnosed with "sleep apnea" (the report puts the diagnosis in quotation marks). The April 2018 sleep study reflects a diagnosis of obstructive sleep apnea. Another VA examination as part of the development of this claim was performed in February 2020. According to the examination report, the Veteran believed that his sleep apnea was caused by his service-connected diabetes, stating that the onset of his sleep apnea occurred after he was diagnosed with diabetes. He also stated he may have had a sleep disorder while on active duty. In the accompanying medical opinion, the examiner concluded that the Veteran's OSA is less likely than not proximately due to or related to his diabetes. The examiner explained that diabetes is an autoimmune condition, and sleep apnea is a mechanical obstruction, and that it is less likely than not that sleep apnea can be caused by any autoimmune disorder. Another VA medial opinion was obtained in January 2021 pursuant to the Board's prior remand directives. The examiner stated that there is "absolutely no correlation" between OSA and diabetes. The examiner explained that OSA is due to airway obstruction, as in a person with chronic sinusitis/rhinitis. The examiner further stated that diabetes is an endocrine disorder manifested by high blood sugars. Therefore, it is less likely than not that the Veteran's OSA is due to or the result of his diabetes. The examiner added that "[a]long the same lines," the Veteran's OSA was not aggravated by diabetes. The Board remanded the claim again for a new VA medical opinion, which was provided in July 2021. The July 2021 VA opinion concludes that the Veteran's OSA was less likely than not proximately caused by or aggravated by his service-connected diabetes mellitus. The opinion explains that obstructive sleep apnea is caused by dynamic narrowing of the upper airway such as closure of the oral pharynx during sleep; it is not caused by diabetes. Regarding direct service connection, the July 2021 VA medical opinion concludes that the Veteran's OSA is less likely than not incurred in or caused by an in-service injury, event, or illness. The examiner explained that the Veteran's service treatment records did not show evidence of a sleep apnea condition during service. Preliminarily, the Board is aware that in the discussion section of its April 2021 remand, the Board found that the January 2021 VA medical opinion is inadequate because it "mostly described what sleep apnea is on [the] one hand and what diabetes is on the other hand without providing further details." The Board further stated that the opinion "failed to specifically discuss the effect of the Veteran's diabetes on his sleep apnea." In this regard, the Board noted that the opinion did not address "whether or not the Veteran's diabetes medications have any impact on the development or progression of his sleep apnea." However, the Board's remand directives themselves merely ask for VA medical opinions regarding direct and secondary service connection, without instructions to the examiner to address the effects of the Veteran's diabetes medications on his sleep apnea or to more specifically discuss how the Veteran's diabetes may affect his sleep apnea. As can be seen, the July 2021 VA medical opinion regarding secondary service connection essentially reiterates the rationale provided in the January 2021 opinion, albeit with less detail. On further review of the record, the Board finds that the existing VA medical opinions are sufficient to make a fully informed decision, and that any failure to comply with the Board's prior remand directives was harmless error. A VA medical opinion is adequate when "as a whole, [it] sufficiently inform[s] the Board of a medical expert's judgment on a medical question and the essential rationale for that opinion." Monzingo v Shinseki, 26 Vet. App. 97, 107 (2012). The "essential rationale" here is obvious. In the January 2021 opinion, the examiner explained that OSA is due to airway obstruction, such as in a person with chronic sinusitis/rhinitis, while diabetes is an endocrine disorder manifested by high blood sugars, and that therefore, it is less likely than not that the Veteran's OSA has either been caused or aggravated by his diabetes. The February 2020 VA medical opinion explains that diabetes is an autoimmune condition, and sleep apnea is a mechanical obstruction, and that it is less likely than not that sleep apnea can be caused by any autoimmune disorder. The November 2017 similarly states that the Veteran's OSA was not caused or aggravated beyond its natural progression by diabetes because an endocrine condition of the pancreas "could/would not cause or aggravate obstruction of the airway[,] which is diagnostic of OSA." The July 2021 opinion provides a similar, if more abbreviated explanation, stating that the Veteran's OSA is less likely than not caused or aggravated by his diabetes because obstructive sleep apnea is caused by dynamic narrowing of the upper airway such as closure of the oral pharynx during sleep. Similarly, the February 2016 VA medical opinion states that OSA is a "separate entity entirely" from diabetes, and that the medical literature did not support a medical relationship. In short, as suggested in the July 2021 opinion, and as stated explicitly in the earlier opinions, the Veteran's diabetes and OSA are unrelated conditions involving distinct bodily systems and anatomical locations, and result from distinct causes, with no linkeither via causation or aggravationbetween them. At this juncture, to ask for further explanation as to why the Veteran's diabetes has not caused or aggravated his OSA is not warranted. The examiners have explained that these conditions are entirely distinct in the bodily systems affected and their underlying causes, with OSA caused by mechanical obstruction of the upper airway, while diabetes is caused by an autoimmune disorder or endocrine condition affecting the pancreas. The examiners have further explained that for the same reasons that the Veteran's diabetes could not cause his OSA, it also could not aggravate his OSA. Further explanation would be superfluous. The regulatory criteria for determining when VA has a duty to provide an examination or obtain a medical opinion under its statutory duty to assist also inform the Board's assessment of the adequacy of the VA medical opinions. The applicable regulation provides, in pertinent part, that VA will provide a medical examination or obtain a medical opinion if the information and evidence of record "[i]ndicates that the claimed disability or symptoms may be associated . . . with another service-connected disability." 38 C.F.R. § 3.159(c)(4). Here, there is no indication in the record that the Veteran's OSA may be associated with his diabetes, either in terms of a causal relationship or in terms of its severity. His bare assertion that the two are related is conclusory. See Waters v. Shinseki, 601 F.3d 1274, 1278-79 (Fed. Cir. 2010) (holding that while competent evidence is not required, a claimant's "conclusory generalized statement that his service illness caused his present medical problems" was not sufficient to trigger the duty to provide an examination or opinion). The fact that he may have experienced OSA symptoms or been diagnosed with OSA after he was diagnosed with diabetesassuming that to be truedoes not in itself indicate that the two conditions are related. Accordingly, as there is no indication in the record that the two conditions may be related, and as VA several VA medical opinions by different medical professionals unanimously find that the Veteran's diabetes could not have caused or aggravated his OSA based on the medical principles involvedas explained in those opinionsthere is simply nothing more for an opinion to address. The Board notes that the April 2021 Board remand mentions the Veteran's medication for diabetes as an example of a factor to consider in terms of any potential effects of his diabetes on his OSA. However, again drawing on the regulatory criteria for determining when VA has a duty to provide an examination or obtain a medical opinion, there is no indication in the record that the Veteran's diabetes medication has had any effect on his OSA. He himself has not made that assertion, and the record does not otherwise reasonably raise that issue. Therefore, the Board finds that the fact that the VA medical opinions do not discuss the Veteran's diabetes medication vis-à-vis his OSA does not render them inadequate, and that an opinion addressing his diabetes medication is not warranted. For the same reasons that the Board finds the VA medical opinions to be adequate to render an informed decision, the Board finds no prejudicial error in any failure to comply with its prior remand directives, as there is no reasonable possibility that such compliance would affect the outcome of the claim. See Stegall v. West, 11 Vet. App. 268, 271 (1998) (noting that the rule of prejudicial error applies to issues with compliance with the Board's remand directives). The Board also observes that the April 2021 remand directives themselves do not contain instructions to address the Veteran's diabetes medication or to provide further discussion as to how the Veteran's diabetes may affect his OSA. Be that as it may, the VA medical opinions clearly explain why the Veteran's diabetes would have no effect on his OSA. The Veteran's generalized and unsupported assertion that his OSA was caused by his diabetes is not probative because it is not supported by an explanation or supporting evidence. Moreover, because he is not shown to have a medical background or medical expertise, he is considered a lay person in the field of medicine. Lay testimony is competent as to matters capable of lay observation or within a person's first-hand experience, and may be competent evidence with respect to both the diagnosis of a medical condition and its etiology or cause. Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009); Jandreau v. Nicholson, 492 F. 3d 1372, 1376-77 (Fed. Cir. 2007). However, lay testimony is not competent with respect to determinations that cannot be made based on lay observation alone due to their medical or scientific complexity. Id; Barr v. Nicholson, 21 Vet. App. 303, 309 (2007); Layno v. Brown, 6 Vet. App. 465, 469 (1994) (holding that lay testimony is not competent to prove that which would require specialized knowledge, training, or medical expertise). In this case, the issue of whether the Veteran's diabetes may have caused or aggravated his OSA is a complex determination that cannot be made based on lay observation alone, and therefore requires medical expertise. Accordingly, the Veteran's unsupported lay opinion is not competent evidence on this issue, and therefore is not probative. See Layno, 6 Vet. App. at 470-71 (holding that in order for testimony to be probative of any fact, the witness must be competent to testify as to the facts under consideration). It is outweighed by the VA medical opinions discussed above. Accordingly, the Board finds that the criteria for service connection for OSA on a secondary basis have not been met. See 38 C.F.R. § 3.310. With regard to direct service connection, the Veteran himself has not really raised this theory of service connection. Rather, in an August 2008 statement, he wrote that he had trouble sleeping during service associated with nightmares and psychological stress, as described in that statement. See August 2008 VA Form 21-4138. Service connection for posttraumatic stress disorder (PTSD) "to include claim for insomnia" has since been granted. His PTSD has been assigned a 30 percent rating, which contemplates symptoms including chronic sleep impairment. 38 C.F.R. § 4.130, Diagnostic Code 9411. The Veteran has not stated that he experienced OSA symptoms during service or was witnessed to have exhibited such symptoms. The March 2012 VA examination report reflects the Veteran's statement that he began having sleep problems in the 1980's. He stated that he had been found to have a deviated septum and enlarged uvula, and that he underwent surgical modification of the upper airway to alleviate snoring and decreased oxygenation. However, over the past ten to fifteen years he had problems with snoring returning and daytime fatigue and hypersomnolence ("narcolepsy"). In short, there is no indication that the Veteran's OSA manifested in service. The July 2021 VA medical opinion concludes, in essence, that the Veteran's OSA is less likely than not related to service because the record does not show that his OSA manifested in service. The Board finds that explanation sufficient to make an informed decision. The "essential rationale" is that in order to find that the Veteran's OSA is directly related to his service, it must have manifested during service. See Monzingo, 26 Vet. App. at 107. As with the secondary service connection opinions, the criteria for determining when VA has a duty to obtain a VA medical opinion informs the Board's assessment of the adequacy of the July 2021 VA medical opinion. VA has such a duty when, in pertinent part, there is an indication that a current disability may be related to an in-service disease, injury, or event. McLendon v. Nicholson, 20 Vet. App. 79, 83 (2006). In this case, there is no indication in the record that the Veteran's OSA may be linked to an in-service disease, injury, or event, which is confirmed by the July 2021 VA medical opinion. Again, the Board notes that the Veteran has not stated that he experienced OSA symptoms in service or had witnessed apneas or OSA symptoms during service. Accordingly, as the record does not show service incurrence or aggravation of a disease or injury related to the subsequent, post-service onset of the Veteran's OSA, the criteria for service connection on a direct basis have not been met. See Holton, 557 F.3d at 1366. As the preponderance of the evidence is against the claim, there is not an approximate balance of positive and negative evidence; therefore, the benefit-of-the-doubt rule does not apply. See Lynch, 999 F.3d at 1395; 38 U.S.C. § 5107. Left Shoulder Disability The Veteran claims service connection for a left shoulder disability, which he states had its onset in January 1970, during active service. See May 2008 VA Form 21-526. For the following reasons, the Board finds that service connection is not established. A March 1970 service treatment record reflects that the Veteran had pain in the right anterior shoulder. His April 1971 separation examination report reflects a normal clinical evaluation of the upper extremities. A VA examination was performed in September 1971 to assess the Veteran's renal colic. The examination report reflects that he stated that for a while during service he had frequent attacks of sore muscles with soreness located in the chest, back, left shoulder, right shoulder, and upper portion of back and in the legs. The examiner's impression was that the Veteran had soreness or myositis in the back muscles which "may very well" have been part of a trichinosis infection or myositis of non-specific origin. A May 2008 authorized release form (VA Form 21-4142) reflects that the Veteran received treatment for his left shoulder by a private physician, J. Gillen, MD, from December 1989 to January 1995. Unfortunately, VA has been unable to obtain the records of that treatment. When VA requested these records, Dr. Gillen's office responded in June 2008 correspondence that it could not locate records for the Veteran, and that he may have been seen at another location. The letter advised that VA forward the request to Bone & Joint Specialists, PC. VA accordingly forwarded the request to that facility. In March 2009 correspondence, that facility stated that the Veteran had not been seen there since 1998, and that the records were no longer available. The VA treatment records reflect that when the Veteran was seen as a new patient, in February 2010, he reported a history of left rotator cuff repair surgery. A VA examination was conducted as part of the development of this claim in December 2017. The report reflects that the Veteran related he had undergone surgery to repair a left rotator cuff tear in 2001. The examiner diagnosed a left shoulder strain. The Veteran attributed the condition to his service, but the report does not specify why he believed it was related to service. Another VA examination was performed in February 2020. The examiner diagnosed a shoulder strain and rotator cuff tear. According to the report, the Veteran stated he believed his left shoulder condition was due to his military occupational specialty (MOS) as a boiler room technician, in which capacity he constantly had to lift his arms over his head. He believed he eventually developed a left shoulder condition as a result. He denied a specific injury to the left shoulder. The examiner opined that the Veteran's left shoulder disability is less likely than not incurred in service or caused by an in-service injury, event, or illness because he did not have any shoulder complaint while on active duty. Another VA medical opinion was obtained in July 2021 pursuant to the Board's April 2021 remand. The examiner concluded that the Veteran's left shoulder disability is less likely than not incurred in service or caused by an in-service injury, event, or illness. The examiner explained, in essence, that the record did not show that the Veteran had a left shoulder condition in service. The Board finds that the February 2020 and July 2021 VA medical opinions are adequate to make an informed decision. They express the "essential rationale" that as the Veteran did not have left shoulder problems during service, the subsequent development of his shoulder condition is not related to service, including repetitive overhead use of the arm in performing his duties as a boiler room technician. See Monzingo, 26 Vet. App. at 107. In other words, the opinions find that if the Veteran's left shoulder condition were related to service, including repetitive use of his arm, there would be evidence of a left shoulder condition at the time. The Board finds that the factual premise underlying the VA medical opinions, namely that a left shoulder condition did not manifested during service, is consistent with the record. In this regard, the Board has considered the fact that in his May 2008 application for service connection, the Veteran wrote "1/1/1970" in the column asking him to state when his left shoulder disability began. See May 2008 VA Form 21-526. That statement in itself is not sufficient to establish the fact. The service treatment records show that the Veteran complained of pain in his right shoulder in March 1970. Thus, as his application for service connection is dated nearly thirty years later, his memory may not have been accurate, and he may have misremembered the right shoulder complaint in March 1970 as a left shoulder condition in January 1970. The Board emphasizes that it does not find the Veteran's entry of "1/1/1970" to necessarily lack credibility; it simply finds that it is not sufficient to establish the fact as his memory might not have been accurate. He has not since that application stated that he experienced left shoulder symptoms in service, or elaborated on the entry of "1/1/1970" in his May 2008 application for service connection. The February 2020 VA examination report states that he believed his left shoulder condition was related to service because he had to constantly lift his arms overhead as a boiler room technician; he did not state he experienced left shoulder problems at the time. As detailed above, efforts to obtain the Veteran's private treatment records, which may have provided important information regarding the history of his left shoulder condition, have been unavailing. The Board further notes that the September 1971 VA examination report, which is dated only a few months after the Veteran's separation from service, states that he related a history of frequent attacks of sore muscles, including in the back, left and right shoulders, chest, and legs. This report indicates that any possible in-service left shoulder symptoms were part of a more generalized condition at the time, which the examiner believed, at least with regard to the back soreness, may be related to trichinosis or myositis. Thus, even if the Veteran had left shoulder pain in service, this report indicates it was not necessarily due to a specific shoulder condition as opposed to a more widespread issue affecting his muscles in multiple areas. The record does not indicate that he currently has either trichinosis or myositis, or that his current left shoulder condition may be related to a history of those conditions. In short, the factual premise underlying the rationales in support of the VA medical opinions, namely that a left shoulder condition did not manifest in service, is consistent with the record. The VA medical opinions are probative, as they represent the conclusions of medical professionals based on review of the claims file and examination (or prior examination) of the Veteran, and are supported by an explanation sufficient for the Board to make a fully informed decision. The Veteran's belief that his current left shoulder disability is related to repetitive overhead use of his arm during active service is not competent evidence, as this is a complex determination that cannot be made based on lay observation alone, given the amount of time that has passed since service. In this regard, the Veteran has not stated that he has experienced left shoulder symptoms ever since service. Accordingly, medical evidence is required. Thus, because he is a lay person in the field of medicine, his belief that his left shoulder disability is related to repetitive use of his arm in service is not competent, and therefore is not probative. See Jandreau, 492 F. 3d at 1376-77; Layno, 6 Vet. App. at 470-71. It is outweighed by the VA medical opinions. Accordingly, as the record does not show service incurrence or aggravation of a disease or injury related to the subsequent onset of the Veteran's left shoulder condition, the criteria for service connection on a direct basis have not been met. See Holton, 557 F.3d at 1366. VA medical opinions were also obtained on the issue of secondary service connection. In the January 2021 VA opinion, the examiner concluded that the Veteran's left shoulder disability is less likely than not the result of the Veteran's service-connected disabilities, including coronary artery disease, diabetes, peripheral vascular disease of the bilateral lower extremities, adjustment disorder (now characterized as PTSD), bilateral hearing loss, tinnitus, kidney stones, and skin melanoma. The examiner explained that these conditions have "nothing to do with the left shoulder disability." The examiner added that the issue of aggravation is a "moot point," since none of these disabilities contribute to or cause the left shoulder disability. The July 2021 VA medical opinion provides a similar explanation, noting that the Veteran's left shoulder condition is "independent" of his service-connected disabilities, and was not caused or aggravated by them. The "essential rationale" in the above opinions is clear as the Veteran's service-connected conditions are entirely distinct from the left shoulder condition in terms of the anatomical location and bodily system affected, they could not have caused or aggravated it. See Monzingo, 26 Vet. App. at 107. As with the claim for OSA discussed above, the criteria for determining when VA has a duty to provide an examination or obtain a medical opinion inform the Board's assessment of the adequacy of the VA medical opinions on this issue in the case at hand. As there is no indication in the record that the Veteran's service-connected disabilities may have caused or aggravated his left shoulder disability, the explanation in the medical opinions that the Veteran's service-connected disabilities have "nothing to do with the left shoulder disability," which is "independent" of those disabilities, is sufficient. See 38 C.F.R. § 3.159(c)(4). The examiners could not be expected to pull out of thin air a discussion of why the Veteran's service-connected disabilities have not caused or aggravated his left shoulder disability, when there is nothing in the record to go by that would suggest the possibility of such a relationship, as confirmed by the opinions themselves. By the same token, any failure to comply with the Board's remand directives on that issue was harmless error. See Stegall, 11 Vet. App. at 271. To the extent the Veteran asserts that his service-connected disabilities have caused or aggravated his left shoulder condition, no explanation in support of that belief has been provided. Moreover, this is a determination that cannot be made based on lay observation alone; indeed, there is no apparent link between the Veteran's service-connected disabilities and his left shoulder condition, either by way of causation or aggravation. Accordingly, his belief that there may be such a relationship is not competent evidence, and therefore not probative. See Jandreau, 492 F. 3d at 1376-77; Layno, 6 Vet. App. at 470-71. It is outweighed by the VA medical opinions. In sum, the criteria for service connection for a left shoulder disability on a secondary basis have not been met. See 38 C.F.R. § 3.310. As the preponderance of the evidence is against the claim, there is not an approximate balance of positive and negative evidence; therefore, the benefit-of-the-doubt rule does not apply. See Lynch, 999 F.3d at 1395; 38 U.S.C. § 5107. REASONS FOR REMAND Entitlement to service connection for a back disability is remanded. The Board regrets the further delay in issuing a decision on the claim for service connection for a back disability, but finds that a new VA medical opinion is warranted, for the reasons that follow. As noted in the Board's April 2021 remand, the service treatment records show that in January 1969 the Veteran sought treatment for back pain that had been present for three days, and which was previously treated by numbing the area and with muscle relaxers. He was assessed with probable viral myositis. The VA medical opinions obtained thus far, including the July 2021 opinion, do not address that evidence. Accordingly, a new VA medical opinion must be obtained that considers the Veteran's in-service back pain. The matter is REMANDED for the following action: Obtain a new VA medical opinion as to whether it is at least as likely as not (50 percent probability or more) that the Veteran's back disability is related to his active service. The claims file must be made available to the examiner for review. The opinion must discuss the Veteran's January 1969 in-service complaint of back pain, which was assessed at the time as probable viral myositis. A complete explanation must be provided in support of the conclusion reached. P.M. DILORENZO Veterans Law Judge Board of Veterans' Appeals Attorney for the Board J. Rutkin, 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.