Comparison of random and postaccident urine drug tests in southern Indiana coal miners.

Background: This study examines the relationship between the use of 9 classes of substances (amphetamines, barbiturates, benzodiazepines, cocaine, marijuana, methadone, opioids, phencyclidine, and propoxyphene) and coal-mining accidents.

Methods: The control sample (n = 215) made up of miners that presented for random urine drug testing. The study sample (n = 100) consists of miners that presented for postaccident urine drug testing. Nonparametric Mann-Whitney U tests of creatinine normalized urine drug levels were conducted to compare the medians of the groups.

Results: The mean drug concentrations were higher in the postaccident group for each drug tested except marijuana. Two-tailed testing demonstrated statistically significant differences for marijuana (P = 0.000), cocaine (P = 0.008), and opiates (P = 0.037).

Conclusions: The study demonstrates statistically significant higher cocaine and opioid concentrations and lower marijuana concentrations in postaccident urine drug tests of coal miners when compared with random tests.