Capturing crack cocaine use: estimating the prevalence of crack cocaine use in London using capture–recapture with covariates

Aim To estimate the prevalence of crack cocaine use in 12 London Boroughs (and London as a whole). Setting Twelve London Boroughs, 2000–01. Methods (1) Covariate capture–recapture techniques applied to three data sources of subjects reporting crack cocaine use: specialist drug treatment (2905), a…