Health conditions among Navy divers at end of service: a retrospective cohort study.

PURPOSE: To identify the most prevalent health conditions among divers during their last year of Navy service. METHODS: For this retrospective descriptive study we used data from the Dive Jump Reporting System to identify 4,623 active-duty divers who separated between 2008 and 2018. Medical records, dive histories, and personnel files were merged, linked and analyzed at the individual level. RESULTS: On average, 420 divers separated each year. Among the separating divers, 99% were male, 26% were aged 25 to 29 years old with a mean age of 35 (SD = 9, range 18 to 65). The major medical categories with the highest numbers of divers affected were: musculoskeletal system diseases (prevalence rate (PR) = 515.2 per 1,000 divers/year); nervous system (PR = 411.9); injury and poisonings (PR = 249.8); and mental disorders (PR = 237.3). Of the 50 specific conditions that affected the most divers the top four were joint disorders (PR = 34.5), disorders of refraction and accommodation (PR = 30.1), back disorders (PR = 26.8) and organic sleep disorders (PR = 21.6). Compared to divers with fewer than 29 dives, divers with 49-plus dives were about twice as likely to have diagnoses related to symptoms involving head and neck. CONCLUSIONS: The study found high rates of conditions such as musculoskeletal disorders, joint and back disorders, and some mental health related disorders. Special warfare divers have high rates of hearing loss, and other disorders of ear. The results show the need and to develop and implement group-specific mitigation programs.

Prescription medication use and trends for U.S. Navy submariners from 2007 to 2018.

Introduction: This is the first study to examine population medication prescription rates among U.S. submariners by common therapeutic classifications. Methods: Individual-level pharmacy records during the years 2007 to 2018 were extracted from the Military Health System's Pharmacy Data Transaction Service (PDTS) file. Demographic and military factors captured from Navy personnel files were linked to PDTS records. Logistic regression models were used to identify characteristics and trends associated with prevalence. Published total rates for other active-duty components were compared to submariner rates. Results: There were data for 50,720 submariners, among whom 576,782 prescriptions were filled. Prevalence rates decreased significantly from 2007-2018 among most drug classes. Central nervous system agents accounted for 31% of the total prescriptions, followed by 12% for eye, ear, nose, and throat preparations, and 10% for anti-infective agents. Higher prescription rates were associated with being enlisted, younger, a woman, lower-ranked, or Hispanic. The mean yearly prescription rate was 2.7 per submariner, less than half of the overall rate of all military components. Conclusion: The survival benefit of HBO2 therapy observed in our unadjusted analysis suggests that there may be therapeutic benefits of HBO2 in treating COVID-19 hypoxia as an adjunct to standard care.

An Approach to Reduce the Incidence of Submarine Medical Evacuations by Identifying Individual Risk Characteristics: Preliminary Findings.

INTRODUCTION: Military medical evacuations (MEDEVACs) are resource intensive and can disrupt operations and decrease readiness. Medical evacuations are a concern for the submarine force because of the limited medical resources onboard, the impact of manpower loss on smaller crews, and the compromise of operational stealth. Although some medical emergencies cannot be avoided, some MEDEVACs may be preventable. However, there is limited knowledge of the underlying causes and risk factors associated with submarine MEDEVACs. This work describes an approach to identify individual characteristics associated with submarine MEDEVACs by presenting preliminary results and next steps. Identifying those most at risk for a MEDEVAC will foster prevention strategies that lead to fewer MEDEVACs, military operation disruptions, missed work and limited duty days, unplanned losses, early separations, and disability compensation claims among navy submariners. MATERIALS AND METHODS: This retrospective study examines MEDEVACs from U.S. Navy submarines from January 1, 2012 to December 31, 2020. Medical evacuation causes were classified by 3 major diagnostic categories: Injury, psychiatric, and medical (i.e., all other non-injury medical events, including dental issues). Diagnostic subcategories were grouped by body region (for injuries) and body system (for non-injuries). Identifiable information from MEDEVAC records were linked to personnel files to capture demographic and occupational variables. Trends across the years were examined, and frequencies and percentages of MEDEVAC cases by both major and sub-diagnostic categories were presented. For cases where both the major diagnostic categories and characteristics were both available, we assessed associations between major diagnostic categories and demographic and occupational characteristics, using Pearson's χ2 test for proportions and Fisher Freeman-Halton exact tests. Pairwise z-tests for proportions were used to determine which proportions differed significantly. RESULTS: A total of 1,283 MEDEVACs were confirmed from 2012 to 2020, with an annual average of 143. Across the years, 24.3% were caused by psychiatric issues (e.g., suicidal ideation), 18.4% were caused by injuries (e.g., blunt trauma), and the remaining 57.3% were caused by other medical emergencies (e.g., gastrointestinal issues). Among the cases linked to personnel files, the major diagnostic category was associated with age, rank, department, and submarine qualification status (group size varied). By age (n = 973), large differences in MEDEVAC causes were seen among submariners 21 to 25 years old who represented 52.4% of psychiatric versus 37.5% of medical MEDEVACs. In contrast, those 35 and older represented 17.0% medical versus 2.7% psychiatric MEDEVACs. CONCLUSIONS: Medical, non-injury cases were the most common cause for a MEDEVAC. There were proportionately more psychiatric than medical cases among younger, less experienced submariners. Conversely, there were proportionately more medical than psychiatric cases among older submariners. A centralized approach to collecting MEDEVAC data is needed. This is the most comprehensive study examining risk factors associated with submarine MEDEVACs. Follow-on work will include adding prior medical waiver requests, health indicators, and confirmed diagnoses to the dataset to conduct a risk analysis. Considering submarines have smaller crews than most surface ships, limited medical assets, and often operate in austere environments, examination of submarine MEDEVACs should be distinct from other navy and military MEDEVACs.

A Preliminary Description of the Health of Women Navy Divers: An Examination of Linked Medical, Personnel, and Dive Log Data for 47 Women Divers Who Separated Between 2008 and 2018.

INTRODUCTION: Although women have always served in the U.S. Armed Forces, it has only been in the last half century that systematic examinations have been done on the health issues experienced by military women. Still, little is known about how occupational health risks among Navy divers might vary between men and women. Our objective was to use available data to examine health issues among all separating divers and then determine how prevalence rates varied between men and women for diagnoses made within the diver's last year of active duty service. MATERIALS AND METHODS: For this retrospective observational study, medical records and personnel data were linked with dive logs at the individual level. We calculated sex-specific prevalence rates and relative risks per 1,000 divers by major diagnostic categories and by specific disease diagnoses. RESULTS: We identified 47 women among the 4,623 active duty Navy divers (1.0%) who separated between 2008 and 2018. Ages varied between 19 and 54 years (M = 33, SD = 8) for women, compared to men who were 18-65 years (M = 35, SD = 9). When compared to men, women had about six times the rate of diseases of the genitourinary system, twice the rate of respiratory system diseases, and about four times as many diagnoses of disorders of the lacrimal system. CONCLUSIONS: The findings of much higher relative risks for women for conditions such as genitourinary disease, skin conditions, and acute respiratory infections require follow-up research to look for causes and potential risk reduction interventions. Future research must determine specific and relative risks as a necessary precursor to developing, implementing, and testing potentially sex-specific risk reduction and health improvement interventions.

Health Conditions Among Navy Submariners at the End of Active Duty; A Retrospective Cohort Study.

INTRODUCTION: Maintaining healthy, well-trained, and highly qualified armed forces is critical for ensuring military readiness. The purpose of this article is to contribute to the body of research focused on the health of U.S. Navy submariners and to identify the health conditions of U.S. Navy submariners during their final year of active duty service. MATERIALS AND METHODS: In this retrospective cohort study, we examined medical records and personnel files of separating U.S. Navy sailors who were: (1) active duty between 2009 and 2018; (2) separated before 2019; and (3) were assigned to a submarine for at least 30 days. Both officers and enlisted service members were included. We linked, described, and analyzed data from the Defense Health Agency, Military Health System Data Repository (MDR), and the Bureau of Naval Personnel (BUPERS). International Classification of Diseases (ICD) diagnoses codes were obtained from MDR. Data collected from BUPERS include age, sex, and rank. We determined the number of individuals who had at least one diagnosed condition (identified as a three-digit ICD code). We report the number of diagnoses and calculate prevalence rates and confidence intervals per condition, as well as prevalence rates per year, using standard formulas. The study was approved by the Naval Submarine Medical Research Laboratory Institutional Review Board. RESULTS: During the study period, 26,014 submariners separated from the Navy. The average number of separations per year was 2,601. About a third of the separating submariners were in the 25 to 29 age group and over 50% were under 30 years of age. Of the three-digit individual ICD codes, some of the highest operationally relevant rates over the 10-year study period (2009-2018) were for joint disorders (prevalence rate [PR] = 180 per 1,000 submariners), back disorders (PR = 128), and sleep disorders (PR = 134). Three mental-health-related conditions were also among the 20 conditions with the highest rates. CONCLUSIONS: High rates of specific diagnoses such as joint disorders indicate the need for additional study to examine causal relationships, to determine which conditions may contribute to lost work time, early separations, or low rates of reenlistment and which conditions might be a result of specific military occupations or duties. Study strengths are the large number of subjects and the long period of observations. A study weakness was the inability to identify submariners who separated because of health conditions. The overall impact of the study is that it identifies urgent health risks and establishes a way to prioritize future research. Future research should include a focus on medically separated personnel; compare rates for submariners to other military groups including all-Navy and all-Department of Defense; and determine specific and relative risks as a necessary precursor to developing, implementing, and testing risk reduction and health improvement interventions.