Occupational correlates of low back pain among U.S. Marines following combat deployment

Many U.S. Marines have experienced routine combat deployments during Operation Iraqi Freedom, which present numerous occupational hazards that may result in low back pain (LBP). The objective of this retrospective cohort study was to identify new-onset LBP among Marines following initial deployment to Operation Iraqi Freedom. Active duty Marines deployed to Iraq or Kuwait between 2005 and 2008 were identified from deployment records and linked to medical databases (n = 36,680). The outcome of interest was an International Classification of Diseases, 9th Revision, Clinical Modification code indicating LBP (724.2) within 1 year postdeployment. Multivariate logistic regression examined the effect of occupation on LBP. Overall, 4.1% (n = 1,517) of Marines were diagnosed with LBP. After adjusting for covariates, the service/supply (odds ratio 1.33, 95% confidence interval, 1.12-1.59) and electrical/mechanical/craftsworker occupations (odds ratio 1.31, 95% confidence interval, 1.12-1.53) had higher odds of LBP when compared to the administrative/other referent group. Within these groups, the highest LBP prevalence was in the construction (8.6%) and law enforcement (6.2%) subgroups. Although infantry occupations purposefully engage the enemy and often face sustained physical rigors of combat, LBP was most prevalent in noninfantry occupations. Future studies should include detailed exposure histories to elucidate occupation-specific etiologies of LBP in order to guide prevention efforts.