Background: A significant proportion of Female Sex Workers (FSWs) as a vulnerable population begin selling
sex at an early age, which may lead the person to develop sexually-transmitted infections (STIs) and human
immunodeficiency virus (HIV). Thus, this study seeks to identify the factors which influence the age of first
sex for sale among the Iranian FSWs.
Methods: In 2010, 872 FSWs from 21 centers in 12 Iranian provinces were selected through multistage
sampling and were interviewed individually by a standard questionnaire. Survival analysis of interval
censored data was used to investigate factors which influence the age of first selling sex. The collected data
were analyzed using Weibull parametric model and the hazard ratio (HR) index was reported. The software
employed in this study was R version 3.4.2 and icenReg package was used.
Findings: The mean age of first selling sex was 24.94 ± 7.34 years. About 22% of the participants started to
sell sex before the age of 18. The risk of experiencing the first selling sex was 23% higher in those individuals
who had experienced alcohol consumption (HR = 1.23) and 51% higher in those who had drug injections
(HR = 1.51). Also, age, education, and marital status were significant variables.
Conclusion: In order to cope with the issue of first selling sex at an early age, the following strategies are
suggested: providing necessary trainings and building culture about the dangers of alcohol consumption and
drug injections, poverty reduction, facilitating education and marriage for young females, and combating sex