Reliability of a Rapid Screener for an Intercept Survey about Drug Use

Background: Intercept surveys are a relatively inexpensive method to rapidly collect data on drug use. However, querying use of dozens of drugs can be time-consuming. We determined whether using a rapid screener is efficacious in detecting which participants use drugs and should be offered a full survey which asks more extensively about use. Methods: We surveyed 103 adults (age 18-29) on streets of Manhattan, NY in 2019 to test the reliability of a screener which queried past-year use of six drugs. Those reporting any drug use on the screener (and a third of those not reporting drug use) were offered the full survey which queried use of 97 drugs. We compared self-reported use on the screener to the full survey. Results: Self-reported use of ecstasy, cocaine, and LSD had high test-retest reliability (Kappa = 0.90-1.00), and the screener had high sensitivity (1.00) and specificity (0.97-1.00) in detecting use of these drugs. Reliability for marijuana (Kappa = 0.62) and nonmedical opioid use (Kappa = 0.75) was lower. The screener had higher sensitivity (0.94) and lower specificity (0.64) in detecting marijuana use, and lower sensitivity (0.71) and higher specificity (0.98) in detecting nonmedical opioid use. Within the full survey, all participants reporting use of amphetamine (nonmedical use), shrooms, poppers, synthetic cannabinoids, synthetic cathinones, novel psychedelics, ketamine, or GHB reported use of at least one drug queried on the screener. Conclusions: Self-reported use of common drugs on a screener can reliably be used as an inclusion criterion for more extensive intercept surveys about drug use behavior.