title: Exploring the impact of consultants' experience on hospital mortality by day of the week: a retrospective analysis of hospital episode statistics.
abstract: OBJECTIVE
  To examine the association of consultants' experience with mortality by day of the week when elective surgery was performed.
  
  
  METHODS
  Retrospective observational study using English hospital administrative data.
  
  
  METHODS
  All acute and specialist English National Health Service (NHS) hospitals carrying out elective surgery between financial years 2008-2009 and 2010-2011.
  
  
  METHODS
  Patients undergoing elective surgical procedures.
  
  
  METHODS
  Death in or out of hospital within 30 days of the surgical procedure taking place.
  
  
  RESULTS
  We examined 3 922 091 (26 409 deaths) elective procedures with valid consultant information between 2008-2009 and 2010-2011 in English hospitals; there were 21 196 consultants in charge of these procedures, which took place in 163 NHS hospitals. Consultant seniority had no significant impact in predicting mortality (p=0.345). Patients undergoing elective surgery under junior consultants had slightly lower odds of 30-day death when compared with patients under more experienced consultants (OR 0.95, 95% CI 0.91 to 0.99). We found significant mortality variation among consultants in charge of elective procedures within hospitals, with only moderate variation between hospitals. The adjusted odds of death remained higher for Friday (OR 1.48, 95% CI 1.42 to 1.54), Saturday (OR 1.97, 95% CI 1.83 to 2.12) and Sunday (OR 1.67, 95% CI 1.50 to 1.85) after adjusting for consultant seniority and patient characteristics. Consultant experience is significantly lower (p<0.0001) on a Friday (median (SD) was 7.9 years (4.4)) than the Monday to Thursday average (median (SD) was 8.5 years (4.3)).
  
  
  CONCLUSIONS
  Our cohort of patients shows that consultant seniority is not a significant factor in predicting 30-day mortality following elective surgery by day of the week. The end-of-the-week effect remains significant after adjusting for patient, consultant and hospital effects, suggesting that other unobserved factors may be driving the higher mortality towards the end of the week. Consultant's years of experience are lowest on a Friday; however, we do not believe that this small variation has any impact on patient outcomes.
authors.affiliation: Dr Foster Unit, Department of Primary Care and Public Health, Imperial College London, London, UK.
authors.forename: Milagros
authors.initials: M
authors.lastname: Ruiz
authors.affiliation: Dr Foster Unit, Department of Primary Care and Public Health, Imperial College London, London, UK.
authors.forename: Alex
authors.initials: A
authors.lastname: Bottle
authors.affiliation: Dr Foster Unit, Department of Primary Care and Public Health, Imperial College London, London, UK.
authors.forename: Paul P
authors.initials: PP
authors.lastname: Aylin
mesh_terms: D000368:Aged; D001071:Appointments and Schedules; D002423:Cause of Death; D002983:Clinical Competence; D016001:Confidence Intervals; D003253:Consultants / Q000706:statistics & numerical data*; D016208:Databases, Factual; D017558:Elective Surgical Procedures / Q000009:adverse effects / Q000379:methods* / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D013222:State Medicine; D013997:Time Factors; D006113:United Kingdom
keywords: Patient safety; Quality measurement; Statistics; Surgery