Estimating the prevalence of individuals likely to use publicly funded alcohol treatment services: an indirect estimation technique

Abstract

Determining prevalence estimates of illicit or stigmatized behaviours is problematic, due to under-reporting and difficulties in sampling adequately populations most at risk of engaging in such behaviours. This has led to the development of indirect prevalence estimation techniques such as multiplier methods, capture-recapture, multivariate indicator methods and back-calculation. This study reports on the development of a treatment multiplier to estimate the number of clients estimated to seek treatment through publicly funded services annually. This study uses a multiplier method of indirect prevalence estimation, using the number of clients receiving publicly funded treatment as the benchmark population. Data for the multiplier were collected through a drug and alcohol telephone information and referral helpline. Participants are callers seeking assistance for their own alcohol use. Results indicate that up to 40 200 individuals (95% confidence interval: 34 900, 47 000) may seek treatment at these agencies annually. This estimate represents a 300% increase in current publicly funded treatment provision. This method was cost-effective and resulted in estimates similar to those obtained through a population-based survey. This method can be adapted easily to areas with a complete registry of clients receiving publicly funded alcohol or drug treatment services and a helpline service with adequate geographic coverage.