Capture-recapture estimates of drug misuse in urban and non-urban settingsin the north east of Scotland

Aims. To estimate the prevalence of opiate or benzodiazepine misuse in the Grampian Health Board area, Scotland and illustrate the use of the capture- recapture method in both rural and urban settings. Design. Capture-recaptur e analyses on six distinct sources of data with unequal coverage of the geo graphical area. Setting. Grampian Health Board area, including the City of Aberdeen. Participants. Data were collated from the Police, Social Work Dep artments, GPs contributing to the Scottish Drug Misuse Database, statutory drug agencies, a voluntary sector drug agency and a needle/syringe exchange . Measurements. In total 1770 individuals were identified as misusing opiat es or benzodiazepines and residing in the Grampian Health Board area; 1129 individuals were resident in the City of Aberdeen. Findings. The total numb er of opiate or benzodiazepine misusers in the City of Aberdeen was estimat ed to be 2519 (95% CI 2048-3200). This figure corresponds to 2.0% (1.6-2.5% ) of the population aged 15-54 years. In a town to the north of Aberdeenshi re where high levels of heroin use had previously been reported in the medi a, 2.5% of the population aged 15-54 (1.8-3.8%) were estimated to be misusi ng opiates or benzodiazepines. Conclusions. Although there may be difficult ies in applying capture-recapture methods in all settings, the methodology can give valuable information on the extent of drug misuse in both urban an d non-urban areas. This information is particularly important to assess the spread of drug misuse from cities to rural areas.