Trends in positive drug tests, United States Air Force, fiscal years 1997-1999

We investigated the relationship between various demographic factors and the risk of testing positive for marijuana or cocaine use in the U.S. Air Force in fiscal years 1997 through 1999. Overall test positive rates for marijuana and cocaine were very low, at 0.24 and 0.07% of all tests, respectively. However, monthly test positive rates increased significantly during the study period while the number of tests conducted decreased by more than 50%. Gender, race/ethnicity, service component, military rank, education level, and assignment location each predicted the likelihood of testing positive for marijuana or cocaine use. These findings were consistent with annual surveys of self-reported drug use conducted in military and civilian populations in the United States. We conclude that overall testing percentages should be re-evaluated in light of these findings, but we do not recommend oversampling from population subgroups that demonstrated a higher likelihood of testing positive.