Capture–recapture estimates of the local and national prevalence of problem drug use in Scotland

Abstract

Estimates of the prevalence of problem drug use, defined within this study as the illicit use of opiates or benzodiazepines, have been provided for all 32 local government areas in Scotland. A national prevalence estimate has been derived as the sum of the local estimates. Data on individual drug users were collated from the police, social work departments, general practitioners, drug treatment services. These data were augmented by the Scottish Drug Misuse Database. In total 22,795 individuals were identified as opiate or benzodiazepine users. This figure corresponds to 0.8% of the population aged 15 to 54. In terms of the national prevalence of problem drug use, it was estimated that there were 55,800 individuals illicitly using opiates and benzodiazepines in Scotland in the year 2000 (95% CI: 43,591–77,697%). That figure corresponds to 2.0% (95% CI: 1.5–2.7%) of the population aged 15 to 54. The local prevalence rates, derived from capture–recapture estimates, ranged from 0.8 to 3.8%. This study has demonstrated that it is possible to use the capture–recapture method in urban and rural areas and, by systematically applying this method at the local level, a national prevalence estimate can be obtained.