The incidence of low back pain in active duty United States military service members.

STUDY DESIGN Epidemiological study. OBJECTIVE To investigate the incidence and risk factors for developing low back pain in active duty military population to include age, sex, race, and rank, and military service. SUMMARY OF BACKGROUND DATA Low back pain is among the most common musculoskeletal conditions worldwide and is estimated to affect nearly two-thirds of the US population at some point in their lives. Low back pain is a multifactorial disease and many risk factors have been implicated including age, race, sex, and marital status. METHODS A query was performed using the US Defense Medical Epidemiology Database (DMED) for the International Classification of Diseases, Ninth Revision, Clinical Modification code for low back pain (724.20). 13,754,261 person-years of data were investigated. Multivariate Poisson regression analysis was used to estimate the rate of low back pain per 1000 person-years, whereas controlling for sex, race, rank, service, age, and marital status. RESULTS The overall unadjusted incidence rate of low back pain was 40.5 per 1000 person-years. Women, compared with men, had a significantly increased incidence rate ratio for low back pain of 1.45. The incidence rate ratio for the 40+ age group compared with the 20 to 29 years of age group was 1.28. With junior officers as the referent category, junior- and senior-enlisted rank groups had increased incidence rate ratio for low back pain, 1.95 and 1.35, respectively. Each service, when compared with the Marines as the referent category, had a significantly increased incidence rate ratio of low back pain: Army: 2.19, Navy: 1.02, and Air Force: 1.54. Compared with single service members, significantly increased incidence rate ratio for low back pain were seen in married service members: 1.21. CONCLUSION Female sex, enlisted rank groups, service in the Army, Navy, or Air Force, age greater than 40 years, and a marital status of married were all risk factors for low back pain.