Longitudinal assessment of self-reported recent back pain and combat deployment in the millennium cohort study

Study Design. A prospective cohort study. Objective. Activities performed during military operations vary in complexity and physical demand. The risk for mental illness following military combat deployment has been well documented. However, information regarding the possible contribution of back pain to decreased mental and functional health is scarce. To our knowledge, this is the first study to prospectively assess deployment and self-reported recent back pain in a populationbased U.S. military cohort. Summary of Background Data. The study consisted of Millennium Cohort participants who were followed for the development of back pain for an average of 3.9 years. Methods. Descriptive statistics and longitudinal analyses were used to assess the temporal relationship of deployment with self-reported recent back pain at follow-up (N = 53,933). Results. Recent back pain was self-reported by 8379 (15.5%) participants at follow-up. After adjusting for covariates, deployers with combat experiences had higher odds [odds ratio (OR) = 1.38, 95% confidence interval (95% CI): 1.28-1.50] of recent back pain than noncombat deployers. There was no association between recent back pain and nondeployers compared with noncombat deployers. Service support/supply handlers were at an increased odds of reporting recent back pain (OR = 1.11, 95% CI: 1.02-1.21) than functional support/administration occupations. Occupations associated with a physically demanding work environment had a higher risk of back pain. Conclusion. Deployers with combat experiences were more likely to report back pain postdeployment. This well-defined group of military personnel may potentially benefit from integrated prevention efforts.