insomnia in higher education: prevalence, validation, and measurement invariance in medical sciences students

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.