The «Weekday Effect» Does Not Have an Impact on the Development of Complications or Mortality After Pulmonary Resection: Retrospective Cohort Study.

Objective: To determine whether elective anatomic pulmonary resection surgery carried out at the end of the week is associated with a higher mortality and postoperative morbidity than surgery performed at the beginning of the week.

Method: Historical cohort study. All patients undergoing anatomical pulmonary resection between January 2013 and November 2018 in our center were included. Patients operated at the end of the week (Thursday or Friday) were considered «not exposed» and patients operated at the beginning of the week (Monday, Tuesday or Wednesday) were considered «exposed». The likelihood of cardiorespiratory complications and operative death (30days) was compared in the two cohorts calculated using the Eurolung1 and2 risk models. 30-day mortality and the occurrence of cardiorespiratory and technical complications were studied as outcome variables. The incidence of these adverse effects was calculated for the overall series and for both cohorts, and the relative risk (RR) and its 95% confidence interval (95%CI) were determined.

Results: The overall mortality of the series was 0.9% (10/1172), the incidence of cardiorespiratory complications was 10.2% (120/1172) and that of technical complications was 20.6% (242/1172). The RR calculated for cardiorespiratory, technical complications and mortality in exposed and unexposed subjects was: 0.914 (95%CI: 0.804-1.039), 0.996 (95%CI: 0.895-1.107) and 0.911 (95%CI: 0.606-1.37), respectively.

Conclusions: Patients operated at the end of the week do not present a higher risk of postoperative adverse effects.