The impact of a 12-hour shift pattern on nurses’ burnout, sickness absenteeism, and fatigue: a single-group pre–post evaluation in a Saudi tertiary-care hospital

Abstract Background Burnout, occupational fatigue, and poor inter-shift recovery remain pervasive among nurses, with downstream effects on absenteeism, retention, and patient safety. This study evaluated whether a hospital-initiated transition from 8- to 12-hour nursing shifts, supported by staff preparation, guaranteed rest-day blocks, and fatigue-management measures, was associated with changes in burnout, occupational fatigue and recovery, and sickness absenteeism at a Saudi tertiary-care hospital. Methods In a single-group pre–post design at a tertiary-care university hospital in the Eastern Province of Saudi Arabia, 146 registered nurses recruited by stratified (day versus night-shift) sampling completed identical assessments immediately before the schedule change, at the end of a six-month period of eight-hour working, and again six months after implementation. Burnout was measured with the 22-item Maslach Burnout Inventory (MBI), occupational fatigue and recovery with the 15-item Occupational Fatigue Exhaustion Recovery (OFER) scale, and sickness absenteeism by self-report. Paired-samples t-tests and the Wilcoxon signed-rank test compared pre- and post-change scores; standardised effect sizes (Cohen’s d₃) and 95% confidence intervals (CIs) were computed for all primary outcomes. Exploratory mixed-design analyses of variance examined whether the magnitude of change varied by clinical unit or years of clinical experience. Results Emotional exhaustion declined from 3.77 ± 1.55 to 3.31 ± 1.77 (mean change 0.46, 95% CI 0.25–0.67; p < 0.001; d₃ = 0.36) and depersonalisation from 2.68 ± 1.53 to 2.42 ± 1.60 ( p = 0.042; d₃ = 0.17), whereas personal accomplishment did not change significantly ( p = 0.293). All three OFER subscales improved, and the total OFER score fell from 4.16 ± 1.22 to 3.70 ± 1.40 (mean change 0.46, 95% CI 0.35–0.57; p < 0.001; d₃ = 0.71). Nurses reporting no sick days rose from 32.4% to 60.3%, (approximately 47 to 88 of 146 participants) and those reporting ≥ 4 sick days fell from 15.7% to 3.4% (Z = − 5.53, p < 0.001; r = 0.46). Conclusion In this uncontrolled evaluation, the move to a 12-hour pattern was associated with lower burnout and occupational fatigue and with reduced self-reported absenteeism, although professional efficacy was unchanged. Because the design had no concurrent control group and the change was introduced as a multi-component package, these associations cannot establish causation and cannot be attributed to the change in shift length alone. For practice, they suggest that where 12-hour schedules are adopted they should be paired with enforced inter-shift recovery, structured fatigue-management support, and routine monitoring of burnout and absenteeism; controlled, longer-term trials are needed to confirm the findings.