Table 3 Multivariate logistic regression analyses of factors associated with willingness to get free HIV testing at MSHRC among IDU in Bangkok, Thailand (n = 244) Variable Adjusted Odds Ratio (AOR) 95% Confidence Interval (CI) p - value Ti et al. BMC Public Health 2012, 12:189 http://www.biomedcentral.com/1471-2458/12/189 Lent or borrowed syringes to/from others* (yes vs. no) Reporting barriers to accessing health services (yes vs. no) (yes vs. no) Ever been to MSHRC Gender (not enrolled in voluntary treatment*) Gender (enrolled in voluntary treatment*) Enrolled in voluntary drug treatment* (male) (male vs. female) (male vs. female) (yes vs. no) (yes vs. no) Enrolled in voluntary drug treatment* (female) *Activities in the previous six months IDU Injection Drug Users treatment being the more willing to get tested at the MSHRC. We found that just over three-quarters (76.2%) of our sample of IDU had previously been tested for HIV in the past six months. Our findings are consistent with previous studies demonstrating fairly high levels of HIV testing in other middle-income settings contending with high rates of HIV infection among IDU, including Andhra Pradesh, India (89%) [22] and St. Petersburg, Russia (76%) [23]. However, our findings are inconsis- tent with previous studies that show low uptake of HIV testing among IDU in Asia [13]. That said, it is unclear whether the high rate of testing observed here is par- tially a reflection of the existence of the tenofovir trial, as 55% of participants had enrolled in this study. Although HIV testing appears to be quite common among IDU in Bangkok, there were still a number of active drug-using participants who had not been tested in the past six months. Among the participants who were not tested for HIV, the majority perceived them- selves to be HIV-negative even though they had engaged in at least one HIV risk behaviour in the past six months. This raises concern that some IDU in Thailand may be unaware of their HIV risk, indicating a need for intensified and targeted outreach, education and testing efforts to reach these individuals [9,24]. Interestingly, our findings reveal that the type of illicit drugs injected (heroin, midazolam, and methamphetamine) was not associated with either of our outcome variables, suggest- ing that our findings are uniform across individuals who use different types of drugs. 1.49 1.22 2.42 2.07 0.22 1.01 9.38 (0.56 - 4.00) (0.59 - 2.51) (1.21 - 4.85) (0.98 - 4.39) (0.03 - 1.85) (0.46 - 2.18) (1.14 - 76.98) UNODC recommends community-based, voluntary drug treatment programs across South East Asia as a substitute for incarceration and compulsory drug deten- tion centres for IDU [25]. Voluntary drug treatment programs, in particular opiate substitution therapy (OST), have been previously associated with a reduction in risky behaviour and HIV infection among IDU in var- ious settings [26-28]. Adding to the benefits of voluntary treatment, we found that participants who were enrolled in voluntary treatment were significantly more likely to get tested for HIV compared to those who were not enrolled in voluntary treatment. Our findings support the recommendation of the United States Centres for Disease Control and Prevention (US CDC) to integrate HIV testing services as part of voluntary drug treatment [29]. However, concerns have been raised about the nat- ure of current HIV testing in voluntary drug treatment centres in Thailand, as it has been reported that in some of these centres, HIV testing is mandatory and a condition of receiving services [11]. Given that our study did not differentiate between mandatory and voluntary HIV testing in voluntary treatment programs, future research should seek to untangle this complex relationship. Nevertheless, in these settings, replacing the system of mandatory testing with voluntary HIV testing in these treatment programs may prove to be effective in increasing the proportion of IDU in Thai- land who get tested, thereby allowing for early diagnosis, enhanced access to antiretroviral therapy (ART) treat- ment, and targeted education and interventions to con- trol the spread of HIV [6]. Page 6 of 9 0.43 0.58 0.01 0.06 0.16 0.99 0.04