Drug use in Australian nightlife settings: estimation of prevalence and validity of self-report

AIMS: This study aimed to 1) estimate the prevalence of illicit drug use in night-time entertainment districts across five major cities in Australia; and 2) validate self-reported drug use using biochemical marker oral swabs. DESIGN: Street intercept surveys and oral drug swabs conducted over a seven-month period during 2011-2012. SETTING: The night-time entertainment districts of three metropolitan cities (Sydney, Melbourne and Perth) and two regional cities (Wollongong and Geelong) in Australia, between the hours of 10 pm and 5 am. PARTICIPANTS: 7,340 individuals agreed to participate in the survey (a 93% response rate). More than half (62%) of the sample was male, with a median age of 22 years (range 18-73). MEASUREMENTS: Patrons were approached in thoroughfares, and while entering and leaving licensed venues. Data collected included demographics and current session alcohol and other substance use. Drug swabs (n = 401) were performed with a sub-sample of participants. FINDINGS: Approximately 9% (95% CI, 7% to 12%) of participants self-reported consumption of illicit or non-prescribed pharmaceutical drugs prior to interview; of those, 81% identified psychostimulants as the drug used. One in five drug swabs returned a positive result, with psychostimulants the most commonly detected drugs (15%; 95% CI, 12%-19%). Kappa statistics indicate agreement between self-report of any illicit drug and a positive drug swab is in the slight range (κ = 0.12 (95% CI, .05 to .20) p = .000). CONCLUSIONS: Self-report findings suggest drug use in the nightlife in Australia is common, though still very much a minority past-time. Drug swabs indicate a higher prevalence of use (20%) than self-report (9%), which suggests that self-reported drug use may not be reliable in this context. This article is protected by copyright. All rights reserved.