Abstract
Introduction: International medical students are exposed to multiple stressors related to academic workload, cultural adaptation, and lifestyle changes, which may negatively influence sleep quality, psychological well-being, and academic performance. The aim of this study was to test the hypothesis that sleep quality, stress levels, and physical activity significantly influence academic achievement among international students at the South Kazakhstan Medical Academy. Materials and Methods: A cross-sectional online survey was conducted between January 20 and January 25, 2026, among third-year international medical students (n=116). Data were collected using a validated English-language questionnaire distributed through Google Forms. Variables included sociodemographic characteristics, sleep behavior, stress level, physical activity, and self-reported academic performance. Descriptive statistics, Spearman’s rank correlation, and Kruskal–Wallis tests were applied. Cluster analysis and predictive modeling were additionally employed to identify behavioral patterns and predictors of academic performance. Results: Late bedtime and insufficient sleep were highly prevalent among participants. Nearly half of the students (47.4%) reported going to sleep after midnight, while 50% experienced insufficient sleep (<6 hours/night). Mean stress level was 5.4 (95% CI = 4.9-5.9) on a 10-point scale, with 25% of students reporting high stress levels (8-10 points). A moderate inverse correlation was identified between sleep duration and stress levels (rs=−0.30, p<0.001), indicating that students with shorter sleep duration tended to experience higher levels of stress. A moderate positive correlation was observed between sleep duration and academic performance (rs=0.35, p<0.001), suggesting that students who slept longer generally achieved higher GPA scores. Cluster analysis identified a “high burnout risk” group comprising 31% of students, characterized by high academic performance despite severe sleep deprivation and elevated stress levels. Predictive modeling demonstrated that sleeping 7–8 hours and maintaining bedtime before midnight significantly improved the probability of higher academic achievement. Conclusion: Sleep duration and circadian rhythm regularity are major determinants of academic performance among medical students, while stress mediates this relationship. Preventive interventions aimed at improving sleep hygiene and reducing stress may enhance both academic success and psycho-emotional well-being.