The prevalence of problem drug misuse in a rural county of England

Previous capture-recapture studies have estimated the prevalence of problem drug misuse in urban areas. This study estimates the prevalence in a rural county, Norfolk, using data from four sources: drug treatment agencies, probation, the arrest referral service, and police (drug-related crime with/without acquisitive crime). Careful consideration was given to methods of matching datasets and sensitivity analyses involved altering matching rules and postcode criteria. Whilst it is recognised that acquisitive crime is often related to drug use, this is the first capture-recapture study to incorporate acquisitive crime data. In further sensitivity analyses the proportion of acquisitive crime assumed to be drug-related was varied from 25-60%. The main analysis provided an estimated prevalence of problem drug use in Norfolk of 2.05% (95% confidence interval: 1.66%-2.56%) for ages 15-54 years, considerably higher than the 1.1% currently suggested for the UK. Sensitivity analyses based on varied matching and postcode criteria produced estimates ranging from 2.41%-3.37%, suggesting our estimate may be conservative. Sensitivity analyses assuming that 25-60% of acquisitive crimes were drug-related, produced estimates ranging from 2.02% to 5.73%, further supporting our main analysis. In conclusion, this study provides evidence that problem drug misuse is more prevalent in this rural population than previously thought.