Richard Hartnoll

A small area analysis estimating the prevalence of addiction to opioids in Barcelona, 1993.

STUDY OBJECTIVE: To determine the distribution of opioid use prevalence in small areas and its relation with socioeconomic indicators. DESIGN: Capture-recapture was applied using data from the Barcelona Drug Information System for 1993 (treatment demands, hospital emergency room visits, deaths from heroin acute adverse reaction and pre-trial prison admissions). To avoid dependence between sources, a log-linear regression model with interactions was fitted. For small neighbourhoods, where capture-recapture estimates were not obtainable, the Heroin Problem Index (HPI) was used to predict prevalence rates from a regression model. The correlation between estimated opioid use prevalence by neighbourhoods and their socioeconomic level was computed. MAIN RESULTS: The citys estimated prevalence was 12.9 opioid addicts per 1000 inhabitants aged 15 to 44 years (95% CI: 10.1, 17.2), which represents 9176 persons. The highest rate was found in the inner city neighbourhood. Comparing rates obtained for each neighbourhood with their unemployment rates, a high correlation coefficient was obtained (r = 0.80, p < 0.001). CONCLUSION: The main contribution of this study is that of combining capture-recapture with the HPI to produce small area prevalence estimates, which would not have been possible using only one method. Areas with higher socioeconomic status showed proportionally low addiction prevalences, but in depressed areas, prevalences varied widely.

Psychosocial Considerations for the Prevention of HIV Infection in Injecting Drug Users

In this article, the authors discuss a study that investigated the meaning that injecting drug users attribute to risk behaviors linked to HIV transmission, especially through the use of nonsterile syringes or the failure to use condoms. To do this, social discourses with respect to the prevention of HIV infection are evaluated. The discussion focuses on how these discourses affect the daily practices of heroin users, practices that in turn influence discourses. Ethnography was used to observe 78 heroin users and 35 people following a methadone treatment program. Observation was carried out in a central district of Barcelona, Spain, with a low socioeconomic level. The results are a useful starting point for generating strategies aimed at preventing HIV transmission among this population on personal, community, and sociostructural levels.