Iskandar et al. BMC Public Health 2010, 10:472 http://www.biomedcentral.com/1471-2458/10/472 Consistent condom use was only reported by 10% of sexually active IDUs [5]. We know of no reported data concerning HIV risk behavior among fIDUs in Indonesia, and fIDUs receive very little attention in current prevention programs in general. This may seriously limit the success of HIV- prevention focusing on drug injection, as a considerable number of IDUs change from injection to non-injection drug administration or completely abstain from illicit drug use [6]. The prevalence of HIV may be high in fIDUs. Transmission of blood borne viruses may con- tinue to occur through sexual behavior and/or by con- taminating equipment that is subsequently used by others for drug use, tattooing and/or piercing [2,7,8]. Furthermore, fIDUs may also play an important role in transmitting HIV infections to the general population because, compared with current IDUs (cIDUs), fIDUs have more sexual contact with people who do not use drugs [9,10]. Hopefully, a better characterization of for- mer IDUs may contribute to improve HIV-prevention. Therefore, the aim of the present study was to explore the characteristics and the risk behavior of former IDUs in Indonesia in comparison with current IDUs. Methods Setting and patients From June to September 2008, 210 IDUs were recruited in Bandung, the capital of West-Java and epicenter of the epidemic of injecting drug use in Indonesia. Respon- dent driven sampling, a form of peer recruitment, was used for recruitment of IDUs from the community [11]. With help from local non-governmental organizations involved in outreach to IDUs, three cIDUs and three fIDUs from different parts of Bandung were selected to act as ‘seeds’ for RDS and invited to a community clinic which has a specific program for IDUs. Following their inclusion in the study, these six seeds were asked to recruit two other persons injecting drugs, either in the last six months (cIDUs) or longer ago (fIDU), by giving individually numbered coupons. IDUs presenting at the community clinic with the coupons, were asked them- selves to recruit two other (current or former) IDUs. This process of recruitment continued until the desired sample size was achieved. Numerical simulations have shown that respondent driven sampling estimates con- verge to the true values even if the seeds are not drawn as desired [12]. As a part of the RDS process, an incentive was offered for participating in the interview ($3) and for recruiting two injecting drug using peers ($2 per eligible peer recruited). After the initial seeds were recruited, only those people who presented coupons were permitted to participate in the study. The study was completely anon- ymous, but to prevent the same participant from Page 2 of 7 entering the study twice, physical marks such as tattoos, scars, or birth marks were recorded. Only those candidates who were or had previously been IDUs were eligible to be included in the study. Two outreach workers from non-governmental harm reduction organizations, both with a previous history of drug use, confirmed that the respondents were indeed IDUs. To this purpose they looked for possible needle tracks, asked each respondent to demonstrate how he/ she injected drugs, and to clarify specific ‘slang’ used by IDUs. All IDUs who passed this screening then provided informed consent. The study was approved by the regio- nal medical-ethical committee (The Health Research Ethics Committee, Faculty of Medicine, Padjadjaran University/Dr. Hasan Sadikin General Hospital Ban- dung) and conducted within the context of program on prevention and treatment of HIV in the context of injecting drug use in Indonesia [13]. Assessment The interview was done at the community health center by trained interviewers who assured all participants that their anonymity would be strictly maintained. All parti- cipants who completed the interview session received a coupon for free HIV, HBV, HCV and syphilis testing at Hasan Sadikin hospital, Bandung. If found positive for HIV, participants were offered CD4-cell counts, chest X-ray and if needed, antiretroviral and/or syphilis treat- ment, all free of charge. The interviewers used two validated questionnaires: the European Addiction Severity Index (EuropASI) and the Blood Borne Virus Transmission Questionnaires (BBV-TRAQ). The EuropASI is an adaptation of the Addiction Severity Index (fifth version). It is a semi- structured interview which takes about one hour, cover- ing issues that may contribute to patients’ substance- abuse problems, such as medical status, employment/ support status, drug/alcohol use, legal status, family social relationship, and psychiatric problems [14]. Parti- cipants are asked if they ever used a number of listed drugs regularly (more than 3 times or 2 consecutive days a week). For regularly used drugs, further informa- tion is recorded including the first time the particular drug was used, the duration of use in a life time, the fre- quency of drug use in the previous 30 days, and drug route of administration [14]. ASI has shown excellent reliability and validity across a range of types of patients and treatment settings in many countries [15]. For the translation into Bahasa Indonesia, WHO translation procedures were used [16]. The BBV-TRAQ questionnaire assesses how often injecting drug users participate in specific injecting, sex- ual and other risk-practices that may expose them to blood-borne viruses. The instrument consists of