Decomposition of Economic Inequality in Needle and Syringe Programs Utilization to its Determinants among Men Who Inject Drugs in Tehran using Blinder-Oaxaca Decomposition Method.

BACKGROUND: According to latest available data there are more of 300,000 people injects drug users (PWID) in Iran.

OBJECTIVES: In this study, we used a Blinder-Oaxaca (BO) decomposition to explore the relative contributions of inequality in utilization of NSPs and to decompose it to its determinants in Teheran.

METHODS: We used data from a cross-sectional survey using snowball sampling to recruit 500 PWID from June to July 2016 in Tehran. Participants were reported injecting drug use in the past month, were able to speak and comprehend Farsi enough to respond to survey questions, and were able to provide informed consent to complete the interview. We used a BO method to decompose the role of economic inequality on utilization of needle and syringe programs.

RESULTS: A total 520 of clients participated in the study of which data was fully complete for 500. The selected predictor variables (age, education level, marital status, homelessness, HIV risk perception, and HIV knowledge) together explain 54% (8.5% out of 16%) of total inequality in utilization of needle and syringe programs and the remaining 46% constitute the unexplained residual. HIV risk perception status contributed about 38% (3.3% out of 8.5%) to the total health inequality, followed by HIV knowledge (26%) and education level were contributed 20% each, respectively.

CONCLUSION: The results showed that contribution of economic inequalities in utilization of NSPs was primarily explained by the differential effects of HIV risk perception and HIV knowledge among PWID. Reducing HIV risk perception and increasing HIV knowledge might be essential to efforts to eliminate inequalities in access to NSPs among PWID.