Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 54 4 2025 04 02 860 869 Amin Moradi Department of Epidemiology, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran Fateme Nikbakht Department of Epidemiology, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran Ali Taghipour Social Determinants of Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Hamid Reza Fathi Secretary of the Coordinating Council for Prevention, Treatment and Harm Reduction of Substance Use Disorders, Mashhad University of Medical Sciences, Mashhad, Iran Behnaz Beygi Department of Epidemiology, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran Khadijeh Ghasemi Department of Epidemiology, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran Zahra Amiri Department of Epidemiology, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran Ehsan Mosafarkhani Department of Epidemiology, Social Determinants of Health Research Center, School of Health, Mashhad University of Medi-cal Sciences, Mashhad, Iran 2024 05 27 2024 11 05 Background: Suicide is a serious global public health issue, which is the fourth-leading cause of death for young people between the ages of 15 and 29. This study aimed to be conducted to investigate the factors affecting suicide reattempts. Methods: This cross-sectional study used data from the Sina Electronic Health Registration System and the HIS of Mashhad University of Medical Sciences, Mashhad, Iran covering around 90% of suicide attempts in Mashhad’s government hospitals (2019–2022). The study population included all Mashhad residents with documented suicide attempts in this period. Descriptive analysis was followed by a Poisson multivariable regression to identify factors affecting suicide attempt frequency, with analyses conducted in Stata version 14 and significance set at P<0.05. Results: Among 5,737 participants, 3,157 (55.0%) were men. The overall rate of suicide reattempt was 10.1% (n=580). Suicide reattempts were more prevalent among men (55.5% of reattempts, n=322), individuals with mental disorders (16.0%, n=93), substance users (7.8%, n=45), single persons (66.6%, n=386), those with high school education (47.6%, n=276), and self-employed individuals (45.7%, n=265). Poisson regression analysis revealed that substance users had a 43% higher likelihood of reattempting suicide compared to non-users (IRR=1.43, 95% CI: 1.27-1.61, p<0.001), after adjusting for other variables. Conclusion: Identifying risk factors for suicide reattempt, such as drug abuse, may be effective in identifying high-risk groups and preventing suicide reattempts. https://ijph.tums.ac.ir/index.php/ijph/article/view/35629 https://ijph.tums.ac.ir/index.php/ijph/article/download/35629/8528