To determine the impact of nighttime intensive care unit (ICU) discharge on patient outcome.
Multiple-center, retrospective observational cohort study.
We used a prospectively collected dataset containing information on 79,090 consecutive admissions from 31 Canadian community and teaching hospitals.
Patients were categorized according to the time of ICU discharge into daytime (07:00–20:59) and nighttime (21:00–06:59). Admissions were excluded if the patients were a) ≤16 yrs of age (392); b) admitted following cardiac surgery (6,641); c) admitted following the initial admission for patients readmitted to the ICU within the same hospital stay (3,632); d) admitted due to a lack of available ward or specialty care beds (457); or c) transferred to another acute care facility (7,724). We found that 62,056 patients were discharged to the ward following the initial ICU admission. Of the 47,062 discharges eligible for analyses, 10.1% were discharged at night. The unadjusted odds of death for patients discharged from ICU at night was 1.35 (95% confidence interval, 1.23, 1.49), compared with patients discharged during the daytime. After adjustment for illness severity, source, case-mix, age, gender, and hospital size, the mortality risk was increased by 1.22-fold (95% confidence interval, 1.10, 1.36) for nighttime discharges. Multivariate regression analysis revealed that patients discharged from the ICU at night have a significantly shorter ICU length of stay than those discharged during the day (p < .001). Whereas hospital length of stay was similar for daytime and nighttime discharges who survived hospital stay, patients discharged at night who did not survive hospital stay had a significantly shorter hospital length of stay (p = .002).
Patients discharged from the ICU at night have an increased risk of mortality compared with those discharged during the day.
From the Department of Medicine, London Health Sciences Centre, London, ON, Canada (FAP, CMM); The Critical Care Research Network, Centre for Critical Illness Research, Lawson Health Research Institute, London, ON, Canada (FAP, CMM); and the University of Western Ontario, Schulich School of Medicine & Dentistry, London, ON, Canada (CMM).
The authors have not disclosed any potential conflicts of interest.