Prevalence and Risk Factors for Musculoskeletal Back Injury Among U.S. Army Personnel.

Introduction: Physical and medical readiness have emerged as a top priority in the army over the last decade. With this emphasis on deployment readiness, it is important to understand key risk factors attributed to common medical problems that arise in our soldiers, including low back pain. The purpose of this study is to elucidate demographic and lifestyle risk factors which would result in seeking medical care for musculoskeletal low back pain among active duty army personnel.

Materials And Methods: A cross-sectional retrospective study investigating all active duty soldiers between October 1, 2016 and September 30, 2018 was performed using the existing Military Health System Data Repository to retrospectively review administrative claims data. Our study queried 39 unique International Classification of Disease codes, 10th Revision codes for low back pain to determine a positive case. We compared those with and without back pain across all variables using a chi-square analysis in SAS. Multivariate logistic analysis was performed to adjust for confounding within any single proposed risk factor and the six other proposed risk factors.

Results: Six hundred fifty seven thousand and six thirty soldiers met inclusion criteria; 228,184 of whom had a medical encounter for low back pain (34.7%). All of the proposed risk factors included statistically significant unadjusted and adjusted odds ratios (ORs) with age conferring the greatest risk in soldiers aged 50-59 with an OR of 2.89 (2.73-3.05) compared to those aged 20-29. Obesity-adjusted OR was 1.77 (1.74-1.80) compared to those who were normal weight. Senior Enlisted status-adjusted OR was 1.34 (1.32-1.36). Females were 66% more likely to have low back pain compared to males with an OR of 1.66 (1.63-1.68).

Conclusion: Disease burden for low back pain tends to be high in the U.S. Army with 34.7% of service members experiencing low back pain. Older age, obesity, and being an enlisted, female service member are risk factors for these musculoskeletal injuries, which is in agreement with previously reported literature on the topic. To mitigate the burden of low back pain, policies and incentives to encourage healthy body mass index and lifestyle are needed. The results of this work inform future studies aimed at further delineating the risk factors found in this study.