Predictors of Positive Drug Screens after Deployment to Iraq or Afghanistan in the Military Drug Testing Program

Aims: Problems associated with alcohol and drug use remain a critical area for intervention development within the Department of Defense (DoD). While there is routine postdeployment screening, drug problems area not documented. This study identifies predictors of testing positive for one or more drugs postdeployment among 306,345 enlisted Army active duty (AD) members returning from Iraq or Afghanistan in FY2008-2011. Methods: Urinalysis tests for cocaine, heroin, THC, amphetamines, and/or designer amphetamines, routinely tested by the DoD, were examined to estimate the percent of the sample with any positive drug test 6-month to 3-year postdeployment (follow up). Demographic and deployment characteristics were examined as potential predictors of a positive drug screen. Multivariate models controlled for study design variables (number of tests, last collection date relative to deployment end). Results: Of AD enlisted members, >80% with urinalysis data were analyzed. Most had at least one random test (median 4) during followup. An estimated 2.74%, 95% confidence interval CI: 2.68–2.89% tested positive. Controlling for design, demographics, and deployment characteristics, with increased odds of a positive drug screen were combat specialist occupation (relative to 4 other groups), in early cohort (deployment began before FY2011), short deployment (relative to 1 year, or >1 year), first deployment (prior deployment ended >365 days before index), and assigned to a Warrior Transition Unit (WTU, rather than regular military duties) upon return. Conclusions: Preliminary findings suggest that combat specialist occupations and first deployers were most at risk. Two measures which may be proxies for returning wounded also had increased odds of a positive drug test. Knowledge of these characteristics may help target new strategies or interventions such as additional screening or brief counseling.