Coverage of overdose prevention programs for opiate users and injectors: a cross-sectional study

Background: The use of opiates, particularly heroin, remains an important cause of morbidity and mortality. Half of the deaths among heroin consumers are attributed to overdose. In response to this problem, overdose prevention programs (OPPs) were designed. The objective of our study was to assess coverage of OPPs among the target population in a specific Spanish region (Catalonia) and to identify characteristics related to attendance. Methods: A cross-sectional survey recruited individuals from outpatient treatment centers (OTCs), therapeutic communities (ThCs), and harm reduction facilities (HRFs) in Catalonia. From 513 participants, 306 opiate users and/or injectors were selected for this study. Coverage was calculated as the proportion of subjects who declared having participated in an OPP. A Poisson regression with robust variance was used to assess factors (socio-demographic aspects and psychoactive substance use patterns) associated to OPP participation, taking into account recruitment strategy. Results: Average age of the 306 subjects was 39.7 years (s.d.: 7.7); 79% were male; 79.2% lived in urban areas and 56.3% were unemployed or had never worked. Overall OPP coverage was 43.5% (95% CI: 37%-49%). Training was received mostly in HRF (60%), followed by OTC (24.4%), prison (19%), and ThC (16%). OPP sessions were attended by 41% of Spanish-born study participants and by 63.3% of foreigners; 92.2% of the participants lived in urban areas. The Poisson regression analysis adjusted by age, sex, and type of recruitment center showed that OPP participation rates were higher for individuals with foreign nationality (PR = 1.3; 95% CI: 1.04-1.72), for those living in municipalities with more than 100,000 inhabitants (PR = 2.0; 95% CI: 1.37-2.81) or the Barcelona conurbation (PR = 2.5; 95% CI: 1.68-3.77), and for those having ever been in prison (PR = 1.6; 95% CI: 1.41-1.81) and had first consumption when they were less than 12 years old (PR = 1.2; 95% CI: 1.06-1.45). Conclusion: Coverage as a whole can be considered high. However, in Catalonia, new strategies ought to be developed in order to attract opiate users and injectors not currently participating, by expanding OPP offer to services and regions where coverage is poor.