Azam Rastegari - Modeling in Health Research Center, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran
Mohammad Reza Baneshi - Modeling in Health Research Center, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran
Ahmad Hajebi - Research Center for Addiction & Risky Behaviors (ReCARB), Psychosocial Health Research Institute, Iran University of Medical Sciences, Tehran, Iran
Alireza Noroozi - Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran
Mohammad Karamouzian - Centre On Drug Policy Evaluation, St. Michael’s Hospital, Toronto, ON, Canada
Mostafa Shokoohi - HIV/STI Surveillance Research Center, and WHO Collaborating Center for HIV, Kerman University of Medical Sciences, Kerman, Iran
Ali Mirzazadeh - HIV/STI Surveillance Research Center, and WHO Collaborating Center for HIV, Kerman University of Medical Sciences, Kerman, Iran
Toktam Khojasteh Bojnourdi - Ministry of Health and Medical Education, Tehran, Iran
Naser Nasiri - HIV/STI Surveillance Research Center, and WHO Collaborating Center for HIV, Kerman University of Medical Sciences, Kerman, Iran
Saiedeh Haji Maghsoudi - Modeling in Health Research Center, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran
Ali Akbar Haghdoost - HIV/STI Surveillance Research Center, and WHO Collaborating Center for HIV, Kerman University of Medical Sciences, Kerman, Iran
Hamid Sharifi - HIV/STI Surveillance Research Center, and WHO Collaborating Center for HIV, Kerman University of Medical Sciences, Kerman, Iran

Background  Estimating the number of people using illicit drugs and alcohol is necessary for informing health policy and programming. However, it is often challenging to reliably estimate the size of these marginalized populations through direct methods. In this study, we estimated the population size of these groups using the indirect Network Scale-Up (NSU) method in Iran from ۲۰۱۵ to ۲۰۱۶.Methods  Using a self-administered questionnaire, we asked ۱۵ ۱۲۴ individuals (۵۴% men) about the number of people they know who used different types of drugs at least once in the past ۱۲ months. Prevalence estimates were reported per ۱۰۰ ۰۰۰ population. The uncertainty level (UL) was calculated using the bootstrap method.Results  The average age of the respondents was ۳۳ years old, and ۳۵.۱% of them were unmarried. The most common drugs and their prevalence were as follows: opium (۲۵۳۴ [۹۵% UL: ۲۴۶۷-۲۵۹۸]), hashish (۸۴۹ [۹۵% UL: ۸۱۱-۸۸۶]), stimulants (methamphetamine, ecstasy pills, cocaine, and Ritalin) (۸۴۲ [۹۵% UL: ۸۰۲-۸۷۹]), heroin/crack (۵۷۸ [۹۵% UL: ۵۵۰-۶۰۷]), and drug injection (۴۵۹ [۹۵% UL: ۴۳۸-۴۸۴]). Additionally, we estimated the prevalence of alcohol use as ۲۷۹۷ (۹۵% UL: ۲۷۳۱-۲۸۶۱). On average, substance use was ۵.۲۳ times more prevalent among men than women. Opium use was more prevalent among individuals aged >۵۰ years old. Moreover, alcohol use was more prevalent among participants between ۱۸ and ۳۰ years old (۵۱۶۴ per ۱۰۰ ۰۰۰ population).Conclusion  Although opium continues to be the most prevalent illicit drug in Iran, the patterns of illicit drug use are heterogeneous among different age groups, genders, and provinces. Age-gender specific and culturally appropriate interventions are warranted to meet the needs of people in different subgroups.

Hidden Groups, Illicit Drug, Network Scale-Up, Alcohol, Iran