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Day of week of procedure and 30 day mortality for elective surgery: retrospective analysis of hospital episode statistics

BMJ 2013; 346 doi: (Published 28 May 2013) Cite this as: BMJ 2013;346:f2424
  1. P Aylin, clinical reader in epidemiology and public health1,
  2. R Alexandrescu, research associate1,
  3. M H Jen, research associate1,
  4. E K Mayer, Walport clinical lecturer2,
  5. A Bottle, senior lecturer in medical statistics1
  1. 1Dr Foster Unit at Imperial College, Department of Primary Care and Public Health, School of Public Health, Imperial College, London W6 8RP, UK
  2. 2Department of Surgery and Cancer, St Mary’s Hospital, Imperial College, London W2 1NY, UK
  1. Correspondence to: P Aylin p.aylin{at}
  • Accepted 4 April 2013


Objectives To assess the association between mortality and the day of elective surgical procedure.

Design Retrospective analysis of national hospital administrative data.

Setting All acute and specialist English hospitals carrying out elective surgery over three financial years, from 2008-09 to 2010-11.

Participants Patients undergoing elective surgery in English public hospitals.

Main outcome measure Death in or out of hospital within 30 days of the procedure.

Results There were 27 582 deaths within 30 days after 4 133 346 inpatient admissions for elective operating room procedures (overall crude mortality rate 6.7 per 1000). The number of weekday and weekend procedures decreased over the three years (by 4.5% and 26.8%, respectively). The adjusted odds of death were 44% and 82% higher, respectively, if the procedures were carried out on Friday (odds ratio 1.44, 95% confidence interval 1.39 to 1.50) or a weekend (1.82, 1.71 to 1.94) compared with Monday.

Conclusions The study suggests a higher risk of death for patients who have elective surgical procedures carried out later in the working week and at the weekend.


  • Contributors: All authors have been involved in the study design, analysis, and manuscript revision. All authors gave final approval of the version to be published. PA is guarantor.

  • Funding: The Dr Foster Unit at Imperial College London is funded by a research grant from Dr Foster Intelligence (an independent health service research organisation). The Dr Foster Unit at Imperial is affiliated with the Imperial Centre for Patient Safety and Service Quality at Imperial College Healthcare NHS Trust, which is funded by the National Institute of Health Research. We are grateful for support from the NIHR Biomedical Research Centre funding scheme.

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at (available on request from the corresponding author) and declare that Dr Foster Unit at Imperial is principally funded via a research grant by Dr Foster Intelligence, an independent healthcare information company and joint venture with the Department of Health.

  • Ethical approval: We have permission from the National Information Governance Board under Section 251 of the NHS Act 2006 (formerly Section 60 approval from the Patient Information Advisory Group) to hold confidential data and analyse them for research purposes (ref PIAG 2-05 (d)2007). We have approval to use them for research and measuring quality of delivery of healthcare, from the South East Ethics Research Committee (ref 10/H1102/25).

  • Data sharing: Data sharing: no additional data available.

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