Psychological Distress, Sleep Quality, and Overall Quality of Life Among Medical Students in a University Mind–Body Exercise Course: An Unlinked Repeated Cross-Sectional Study

Background/Objectives: Psychological distress, poor sleep quality, and reduced quality of life commonly co-occur among medical students, yet their mutually adjusted relationships remain less well characterised within curriculum-based mind–body exercise settings. We examined whether these relationships were replicated across two unlinked survey waves and whether psychological distress and sleep quality remained associated with overall quality of life after mutual adjustment. Methods: An unlinked repeated cross-sectional study was embedded within a 12-week university Wuqinxi mind–body exercise course. Anonymous surveys were administered at course initiation (T0) and completion (T1), with 184 valid responses at each wave. Psychological distress, sleep quality, and overall quality of life were assessed using the DASS-21, PSQI, and the PROMIS Global Health Global02 item, respectively. Spearman correlations and proportional-odds ordinal logistic regression were performed with adjustment for sex, age, and previous mind–body exercise experience. Holm correction was applied. Results: Associations among the three health domains were directionally consistent at both waves (|ρ| = 0.359–0.494; all Holm-adjusted p < 0.001). In mutually adjusted models, poorer sleep quality was associated with lower odds of higher overall quality of life at T0 (OR per SD = 0.375, 95% CI 0.269–0.522) and T1 (OR per SD = 0.400, 95% CI 0.287–0.558; both Holm-adjusted p < 0.001). Associations for psychological distress were weaker and did not remain statistically significant after multiplicity correction. Conclusions: Across two unlinked survey waves embedded in a 12-week Wuqinxi course, poorer sleep quality remained associated with lower overall quality of life after adjustment for psychological distress and measured covariates, whereas the corresponding association for psychological distress was weaker. These findings characterise concurrent health relationships within the intervention context but do not establish within-person change or causal effects of Wuqinxi.