Journal of Medical Education Development

en Insomnia in higher education: Prevalence, validation, and measurement invariance in medical sciences students آموزش پزشکی Medical Education پژوهشي اصیل Orginal Research Background & Objective: Insomnia, a widespread sleep disorder, impacts 15-35% of the general population and a concerning 30% of medical sciences students. This study aims to assesses the psychometric properties, factor structure and measurement invariance of the Insomnia Severity Index (ISI) in Iranian medical university students. Materials & Methods: This cross-sectional study included 370 medical university students (54.9% females). After providing a detailed introduction regarding the purpose of the study and receiving participants' consent online, they were requested to fill out the Insomnia Severity Index (ISI) and Pittsburgh Sleep Quality Index (PSQI). Confirmatory factor analysis and hierarchical regression analysis were used to examine the factor structure and predict insomnia severity. Results: The results of descriptive statistics showed that the prevalence of clinical insomnia was 22.6% in male and 27.9% in female students, and 62.2% of male and 67.5% of female students had poor sleep quality. CFA showed that the one-factor model with all items was the most suitable structure (x2 = 13.82, df = 9, GFI = 0.990, CFI = 0.994, TLI = 0.986, RMSEA = 0.038). The study's findings indicate that the ISI exhibits measurement invariance across genders, ensuring its unbiased application for both male and female populations. Furthermore, this scale demonstrated acceptable reliability and validity. Finally, the results of hierarchical regression analysis indicated that the poor sleep quality was a significant predictor of insomnia severity (β = 0.389). Conclusion: The Persian version of ISI showed strong validity and reliability. These findings indicate that insomnia severity could be measured adequately in Iranian samples using the ISI. medical students, insomnia disorder, prevalence study, psychometrics 32 41 http://edujournal.zums.ac.ir/browse.php?a_code=A-12-2339-1&slc_lang=en&sid=1 Zahra Nejad-Ebrahim zahra.nejadebrahimz@gmail.com 5300319475328460033431 0009-0009-4924-6531 No Student Research Committee, Department of Clinical Psychology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran Amirhossein Rasouli amirhs.rasouli@gmail.com 5300319475328460033432 0009-0000-9519-0887 No Student Research Committee, Department of Clinical Psychology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran Hatef Tirgari Seraji hatef.tirgari76@gmail.com 5300319475328460033433 0009-0008-6837-7708 No Department of Psychology, Faculty of Educational Sciences and Psychology, University of Mohaghegh Ardabili, Ardabil, Iran Sima Jahanbakhsh j_sima94@yahoo.com 5300319475328460033434 0009-0005-4829-4049 No Student Research Committee, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran Omid Saed o.saed@zums.ac.ir 5300319475328460033435 5300319475328460033435 Yes Department of Clinical Psychology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran