Abstract
BACKGROUND: Around the world, one of the main concerns and risky behaviors among youths is methamphetamine consumption. Since the age of onset of methamphetamine use is decreasing, therefore, it is important to identify the effective factors on the age of onset of methamphetamine consumption. In the present study, factors affecting the age of onset of methamphetamine consumption was studied in Iranian youths aged 19-29 years. METHODS: In this cross-sectional nationwide study, individuals aged 19-29 years were selected through multistage cluster sampling and convenience sampling method from 13 provinces in Iran. People completed the questionnaire pertaining to knowledge, attitude, and history of methamphetamine consumption. In order to investigate the factors effective on the age of onset of methamphetamine consumption, we used the Weibull parametric model for data with doubly censored characteristic. FINDINGS: 3246 people participated in this study, half of whom were men and mostly single (60.3%), university student or graduate (50.2%), and unemployed (58.1%). Nearly 6% of participants have ever used methamphetamine. Mean and standard deviation (SD) of age of onset of methamphetamine use was 20.3 ± 3.3 years. Data analysis indicated that the variables of gender, marital status, education, knowing a methamphetamine consumer, knowing an ecstasy consumer, ecstasy consumption, illegitimate sex, attitude towards methamphetamine, and age group were the factors affecting the age of onset of methamphetamine consumption. CONCLUSION: The results can contribute to the policy-makers to take the necessary interventions on the factors affecting the age of onset of methamphetamine consumption to reduce the methamphetamine consumption, especially in the critical young ages.