Purpose Ambulatory surgery is generally considered safe; however, as many as 3% of patients require unplanned acute postoperative care. The purpose of this study was to measure the impact of the day of the week of surgery on the outcomes of ambulatory surgery. Methods Using population-based health administrative data, we conducted a historical cohort analysis by identifying patients who underwent ambulatory surgery from 2002-2012. Multivariable regression was used to measure the association between the day of the week of surgery and the primary outcomes of 30-day emergency department (ED) visit or hospital readmission after successful discharge on the day of surgery. The secondary outcome that was similarly compared was unsuccessful discharge on the day of surgery. Results Of 296,497 patients identified, 32,100 (10.5%) returned to the ED or were readmitted to hospital within 30 days. Adjusting for demographics, comorbidities, and preoperative use of health resources, Friday surgery was most associated with the primary outcome (adjusted hazard ratio, 1.07; 95% confidence interval, 1.03 to 1.11) when compared with Monday surgery. This association was stronger in certain surgery types. There were 9,197 (3.1%) patients who were not discharged on the day of surgery; no association between day of the week and unsuccessful discharge was identified. Conclusion On a population level, there was a small effect of the day of the week of ambulatory surgery on outcomes; however, the clinical impact is likely not relevant. Certain surgical types may be more susceptible to a day of the week effect, but more research is needed to elucidate this notion.
RésuméObjectif En règle générale, les chirurgies ambulatoires sont considérées comme étant sécuritaires; toutefois, jusqu'à 3 % des patients nécessitent des soins postopératoires aigus non planifiés. L'objectif de cette étude était de mesurer l'impact du jour de la semaine durant lequel la chirurgie a eu lieu sur les pronostics de chirurgie ambulatoire. Méthode À l'aide des données administratives de santé basées sur la population, nous avons réalisé une analyse de cohorte historique en identifiant les patients ayant subi une chirurgie ambulatoire entre 2002 et 2012. Nous avons utilisé une analyse par régression multivariée pour mesurer l'association entre le jour de la semaine au