Change in drug-using networks of injecting drug users during methadone treatment: a pilot study using snowball recruitment and intensive interviews.

This pilot study used snowball recruitment methods and intensive interviews to assess personal drug-using networks and HIV risk behavior of injection drug users (IDUs). Index subjects were 22 methadone maintenance patients reporting current drug injection who were interviewed about personal drug-using networks both current and prior to treatment entry. The index subjects were then asked to recruit other network members to the study. Ninety-seven network members were identified and 40 interviewed, including 18 not in treatment. Index IDUs reported fewer co-IDUs for the treatment period than the pretreatment period, suggesting a reduction in risk of exposure to HIV. The combination of snowball recruitment and intensive interview procedures constitutes a useful method for studying IDU networks.