Khaled Rahmani - Assistant Professor of Epidemiology, Social Determinants of Health Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
Ebrahim Ghaderi - Associate Professor of Epidemiology, Social Determinants of Health Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
Farzam Bidarpoor - MD, MPH, Vice Chancellor of Deputy of Health, Kurdistan University of Medical Sciences, Sanandaj, Iran

Background and Aim : Addicts especially injecting drug users (IDUs) are one of the out-reach groups; to conduct harm reduction and other intervention programs for them it is necessary to estimate the size of their population. This study was conducted to estimate the population size of injecting drug users in the city of Sanandaj in 2015.Methods : In this cross-sectional study, we used a capture-recapture analysis based on three sources of information: Drop-in center (DIC) of Kurdistan University of Medical Sciences in Sanandaj, DIC of State Welfare Organization of Sanandaj, and Triangle clinic of central prison of Sanandaj. Then, using the capture-recapture method and Peterson-Lincoln, Bailey s Modification, and Chapman estimators the population of injecting drug users was estimated.Results : The number of IDUs registered in DIC of Kurdistan University of Medical Sciences, DIC of State Welfare Organization of Sanandaj, and Triangle Clinic central prison of Sanandaj were 27, 59, and 65 persons, respectively. Finally, the total size of IDUs was estimated to be 559; it indicates that 24.3% are under the coverage of harm reduction programs.Conclusion : The prevalence of drug injection in Sanandaj is still high, hence it is important to design harm reduction programs for this group

Injecting Drug users; hard-reach population; capture-recapture; Sanandaj