Oral fluid device performance in identifying amphetamine, methamphetamine, and cocaine use in Brazilian drivers

Stimulant use while driving is a high-risk factor for collisions and fatalities. In recent years, several strategies to curtail impaired driving were employed on highways, including on-site oral fluid testing. This study evaluated four roadside oral fluid testing devices (AquilaScan®, Dräger DrugTest®, Druglizer®, and DrugWipe®) for the detection of amphetamine, methamphetamine, and cocaine in oral fluid from Brazilian drivers. Overall, 8985 screening tests were conducted, and LC-MS-MS analysis was performed on 46% of the oral fluid samples. Screening and confirmatory test results were compared considering the manufacturers' and Substance Abuse and Mental Health Services Administration's recommended cutoff concentrations. Performance reliability data are available for well-known oral fluid screening devices such as the Dräger DrugTest® or Securetec DrugWipe®, but most evaluations were based on highly prevalent cannabinoid results. In many cases, there were insufficient data to evaluate performance of other drug classes, including reliability data for amphetamines and cocaine that are presented here. Approximately, 3.0% of samples screened positive for amphetamine, 0.9% for methamphetamine, and 2.6% for cocaine. Efficiency was higher than 93.9% for all devices, but other parameters varied considerably, with sensitivity 56.4-100% and positive predictive value 4.2-87.1%. When considering the recommended minimum of 80% performance criteria suggested by the Driving Under the Influence of Drugs, Alcohol, and Medicines study, the Dräger DrugTest® was the only device to achieve satisfactory sensitivity, specificity, and efficiency for these stimulants at multiple evaluated cutoffs. Given the observed variability between devices, a detailed evaluation of the analytical performance of roadside oral fluid testing devices is advised before implementation in traffic enforcement actions.