How well do trends in incidence of heroin use reflect hypothesised trends in prevalence of problem drug use in the North West of England?

Abstract

This study investigates whether hypotheses about trends in the prevalence of problem drug use (PDU), prompted by capture--recapture based age-specific prevalence estimates, are corroborated by estimates of trends in incidence. Lag correction techniques were used to provide incidence estimates adjusted for the time-lag between onset of drug use and its first recorded treatment for heroin users seeking treatment in three areas of North West England between 1986 and 2000 (n = 4142). The incidence trends indicated geographical variation in the progress of heroin ‘epidemics’ in the areas studied and corroborated previously estimated prevalence rates that suggested PDU has passed its peak and is declining in some areas, but continues to increase in others. The lag correction method is capable of producing estimates that will improve our understanding of changes in the size and composition of the population targeted for drug misuse treatment and may provide a basis on which to forecast the direction of future trends.

• Problem drug use
• incidence
• prevalence
• lag-correction
• capture–recapture

Competing Interest Statement

The authors wish to declare that they have no competing interests.