Abstract
BACKGROUND: The aim of this study was to evaluate if the time of day a cholecystectomy was performed affects in-hospital complication rates and mortality. METHODS: A national quality measurement database was retrospectively studied. Study period was 2010 to 2017. The inclusion criteria were operatively treated cholecystitis or another benign disease of the gallbladder. Further, the time of day the operation was performed must have been documented. We defined nighttime as all interventions performed between 7PM until 6AM. A total of 11'459 patients were included. Development of any complication during hospitalization and in-hospital mortality was the main outcomes. The first part of the study was solely descriptive. In the second part, we applied a 1:1 case-control-matching. A matched group of 274 pairs were further investigated. RESULTS: Only 8.4% of the procedures were performed during nighttime. Complications occurred in 6.7% of all patients. We found twice as many complications in the nighttime group compared to the daytime group. Mortality was 0.56% during daytime and 0.52% during nighttime. In a matched-pair analysis, however, we found no significant differences in the overall mortality rate nor in the occurrence of complications when comparing day- vs. nighttime operations. CONCLUSIONS: We found twice as many complications in the nighttime group (12%) compared to the daytime group (6.1%), mainly related to patient risk factors. In contrast to common apprehension, however, nighttime cholecystectomies were not associated with higher mortality rates.