title: Weekday of oesophageal cancer surgery in relation to early postoperative outcomes in a nationwide Swedish cohort study.
abstract: Later weekday of surgery for oesophageal cancer seems to increase 5-year mortality, but the mechanisms are unclear. We hypothesised that early postoperative reoperations and mortality might explain this association, since reoperation after oesophagectomy decreases long-term prognosis, and later weekday of elective surgery increases 30-day mortality.
  
  
  
  This was a population-based cohort study during the study period 1987-2014.
  
  
  
  All Swedish hospitals conducting elective surgery for oesophageal cancer in Sweden.
  
  
  
  Included were 1748 patients, representing almost all (98%) patients who underwent elective surgery for oesophageal cancer in Sweden during 1987-2010, with follow-up until 2014.
  
  
  
  The risk of reoperation or mortality within 30 days of oesophageal cancer surgery was assessed in relation to weekday of surgery by calculating ORs with 95% CIs using multivariable logistic regression. ORs were adjusted for age, comorbidity, tumour stage, histology, neoadjuvant therapy and surgeon volume.
  
  
  
  Surgery Wednesday to Friday did not increase the risk of reoperation or mortality compared with surgery Monday to Tuesday (OR=0.99, 95% CI 0.75 to 1.31). A decreased point estimate of reoperation (OR=0.88, 95% CI 0.64 to 1.21) was counteracted by an increased point estimate of mortality (OR=1.28, 95% CI 0.83 to 1.99). ORs did not increase from Monday to Friday when each weekday was analysed separately. There was no association between weekday of surgery and reoperation specifically for anastomotic leak, laparotomy or wound infection. Stratification for surgeon volume did not reveal any clear associations between weekday of surgery and risk of 30-day reoperation or mortality.
  
  
  
  Weekday of oesophageal cancer surgery does not seem to influence the risk of reoperation or mortality within 30 days of surgery, and thus cannot explain the association between weekday of surgery and long-term prognosis.
authors.affiliation: Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden Section of Gastrointestinal Cancer, Division of Cancer Studies, King's College London, London, UK.
authors.forename: Jesper
authors.initials: J
authors.lastname: Lagergren
authors.affiliation: Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Mattsson
authors.affiliation: Surgical Care Science, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Pernilla
authors.initials: P
authors.lastname: Lagergren
mesh_terms: D000368:Aged; D057868:Anastomotic Leak / Q000601:surgery; D017558:Elective Surgical Procedures / Q000706:statistics & numerical data; D004938:Esophageal Neoplasms / Q000401:mortality* / Q000601:surgery*; D016629:Esophagectomy / Q000009:adverse effects / Q000401:mortality* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012086:Reoperation / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013530:Surgical Wound Infection / Q000601:surgery; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors
keywords: 30-day mortality; Day of surgery; Oesophageal neoplasm; Postoperative reoperation; Short-term outcomes