Within-person differences in night-shift burden and well-being after ICU versus non-ICU night shifts among resident physicians: a paired survey study

BACKGROUND: Night shifts are integral to residency training but may disrupt sleep and recovery. ICU versus non-ICU comparisons are often confounded by between-person differences, and night-shift exposure is often operationalized using simple shift counts rather than more proximal indicators of sleep disruption and recovery. METHODS: We conducted a single-center within-person paired survey study (August 2025-January 2026) in a tertiary teaching hospital. Residents completed the same questionnaire within 24 h after one non-ICU night shift (T1) and after their second ICU night shift (T2). Night-shift burden was assessed using self-reported indicators including duty duration, sleep during the shift, work-related awakenings/calls, and post-shift recovery. Within-person ICU versus non-ICU differences were examined using paired analyses. Associations with emotional exhaustion were evaluated using generalized estimating equations (GEE) with a Gaussian family, exchangeable working correlation structure, robust standard errors, and prespecified burden indicators. RESULTS: Sixty-one residents provided paired responses. Compared with non-ICU night shifts, ICU night shifts were characterized by higher duty duration category (P < 0.001), sleep during the shift shifted toward lower categories (1.95 ± 0.72 vs. 2.72 ± 0.92; P < 0.001), and work-related awakenings/calls shifted toward higher categories (3.39 ± 0.71 vs. 2.79 ± 0.99; P < 0.001). Emotional exhaustion was higher after ICU night shifts (mean paired difference + 3.39; 95% CI 1.00 to 5.79; P = 0.006), and life satisfaction was lower (- 8.90; 95% CI - 11.41 to - 6.40; P < 0.001). In the adjusted GEE model, ICU timepoint remained associated with higher exhaustion (β = 2.94; 95% CI 0.12 to 5.76; P = 0.041), and work-related awakenings/calls were strongly associated with higher exhaustion (β = 3.37; 95% CI 1.37 to 5.38; P < 0.001). CONCLUSIONS: Within the same residents, ICU night shifts were associated with greater night-shift burden and poorer immediate well-being than non-ICU night shifts. These findings should be interpreted in light of the single-center design, modest sample size, self-reported measures, and fixed measurement order. A multidimensional burden framework may help training programs identify modifiable aspects of night duty, including sleep opportunity, interruption load, and recovery time.