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Original article

Vol. 149 No. 1112 (2019)

Uncertain progress in Swiss perioperative mortality 1998–2014 for 22 operation groups

  • Johannes Wacker
  • Marcel Zwahlen
Cite this as:
Swiss Med Wkly. 2019;149:w20034



The perioperative mortality rate (POMR) is used as a quality indicator to monitor health care system performance at regional and national levels. The Swiss Federal Office of Public Health publishes national in-hospital mortality rates for several indicator conditions and indicator operation types (IORs). We investigated long-term time trends of POMRs from 1998–2014. In view of continual advances in perioperative care, we expected to find decreasing trends.


Non-cardiosurgical IORs containing aggregated age- and sex-specific data (number of operations and deaths) for all years of the study period were included to calculate age-standardised POMRs using the 2013 European Standard Population. We assessed calendar time trends of POMRs using multivariable Poisson regression. We categorised IORs according to the type of time trend (decreasing, unchanged, or increasing incident rate ratio) and mean risk levels (age-adjusted POMR).


A total of 22 IORs were included, comprising 1,561,012 operations and 22,140 deaths (overall crude POMR 1.42%). POMR trends decreased for 6 IORs representing 26.8% of operations, remained unchanged for 13 IORs (56.9% of operations), and increased for 3 IORs (16.4% of operations). IOR categorisation according to POMR trends and to risk levels yielded four groups. (1) Decreasing POMR trends, low- to intermediate-risk IORs (age-adjusted POMR 0.2–2.2%): cholecystectomy; arterial pelvic/leg aneurysm or dissection operation; femoral neck fracture; trochanteric fractures; gastric, duodenal or jejunal ulcer resection; major pulmonary or bronchial resection. (2) Unchanged POMR trends, low-risk IORs (0.1–0.9%): transurethral resection of the prostate (TUR prostate); hernia repair without intestinal operation; hysterectomy; extracranial vascular operation; nephrectomy; amputation foot, non-traumatic. (3) Unchanged POMR trends, intermediate-risk IORs (1.7–3.8%): hernia repair with intestinal operation; gastric carcinoma resection; non-ruptured abdominal aortic aneurysm (open operation); arterial pelvic/leg thromboembolic operation; colorectal resection, pancreatic resection; complex oesophageal procedure. (4) Increasing POMR trends, low- to high-risk IORs (0.1–5.2%): hip endoprosthesis; cystectomy; amputation lower limb. Impact of sex on POMR: hysterectomy and TUR prostate comprised 19.7% of all operations; among the remaining operations, 68.5% showed significantly lower and 27.1% significantly higher POMRs in females. 4.4% showed no sex difference.


In Switzerland, in-hospital POMR trends from 1998–2014 were unchanged or even increasing for the majority of IORs (73% of included operations). Our analysis used age-standardisation but cannot account for changes in coding practices and organisation of healthcare delivery. POMR trends should be systematically monitored at the national level and used to guide priorities in national quality improvement strategies.


  1. Ariyaratnam R, Palmqvist CL, Hider P, Laing GL, Stupart D, Wilson L, et al. Toward a standard approach to measurement and reporting of perioperative mortality rate as a global indicator for surgery. Surgery. 2015;158(1):17–26. doi:.
  2. Watters DA, Guest GD, Tangi V, Shrime MG, Meara JG. Global surgery system strengthening: it is all about the right metrics. Anesth Analg. 2018;126(4):1329–39. doi:.
  3. Palmqvist CL, Ariyaratnam R, Watters DA, Laing GL, Stupart D, Hider P, et al. Monitoring and evaluating surgical care: defining perioperative mortality rate and standardising data collection. Lancet. 2015;385(Suppl 2):S27. doi:.
  4. Watters DA, Hollands MJ, Gruen RL, Maoate K, Perndt H, McDougall RJ, et al. Perioperative mortality rate (POMR): a global indicator of access to safe surgery and anaesthesia. World J Surg. 2015;39(4):856–64. doi:.
  5. World Health Organization. Global reference list of 100 core health indicators. Geneva: World Health Organisation; 2018 [cited 2018 September 15]. Available from:
  6. The lancet commission on global surgery. 2018 [cited 2018 Aug 28]. Available from:
  7. Meara JG, Leather AJM, Hagander L, Alkire BC, Alonso N, Ameh EA, et al. Global Surgery 2030: evidence and solutions for achieving health, welfare, and economic development. Lancet. 2015;386(9993):569–624. doi:.
  8. Watters DA, Babidge WJ, Kiermeier A, McCulloch GA, Maddern GJ. Perioperative mortality rates in Australian public hospitals: the influence of age, gender and urgency. World J Surg. 2016;40(11):2591–7. doi:.
  9. Pearse RM, Moreno RP, Bauer P, Pelosi P, Metnitz P, Spies C, et al.; European Surgical Outcomes Study (EuSOS) group for the Trials groups of the European Society of Intensive Care Medicine and the European Society of Anaesthesiology. Mortality after surgery in Europe: a 7 day cohort study. Lancet. 2012;380(9847):1059–65. doi:.
  10. Ghaferi AA, Birkmeyer JD, Dimick JB. Variation in hospital mortality associated with inpatient surgery. N Engl J Med. 2009;361(14):1368–75. doi:.
  11. Wang Y, Eldridge N, Metersky ML, Verzier NR, Meehan TP, Pandolfi MM, et al. National trends in patient safety for four common conditions, 2005-2011. N Engl J Med. 2014;370(4):341–51. doi:.
  12. Wacker J, Staender S. The role of the anesthesiologist in perioperative patient safety. Curr Opin Anaesthesiol. 2014;27(6):649–56. doi:.
  13. BAG. Qualitätsindikatoren der Schweizer Akutspitäler - Indicateurs de qualité des hôpitaux suisses de soins aigus - Indicatori di qualità degli ospedali per cure acute svizzeri 2014. 2016 [cited 2018 Jan 17]. Available from:
  14. ANQ - Nationaler Verein für Qualitätsentwicklung in Spitälern und Kliniken. ANQ Messergebnisse Akutsomatik 2017 [cited 2019 Sept 18]. Available from:
  15. Schweiz P. Operation Sichere Chirurgie: gelungen? 2015 [cited 2018 September 15]. Available from:
  16. Kohn LT, Corrigan JM, Donaldson MS. To err is human: building a safer health system. Washington, D.C.: National Academy Press; 2000.
  17. Classen DC, Resar R, Griffin F, Federico F, Frankel T, Kimmel N, et al. ‘Global trigger tool’ shows that adverse events in hospitals may be ten times greater than previously measured. Health Aff (Millwood). 2011;30(4):581–9. doi:.
  18. Jüni P, Hossmann S, Rat J, Limacher A, Rutjes AWS. Inter-cantonal agreement on highly specialised medicine (IVHSM): rarity as the criterion for the centralization of highly specialised medicine. Bern: Institute of Social and Preventive Medicine, University of Bern; 2014 [cited 2018 May 11]. Available from:
  19. Eurostat. Revision of the european standard population. Luxembourg: Publications Office of the European Union; 2013 [cited 2016 June 12]. Available from:
  20. Kirkwood BR, Sterne JAC. Poisson regression. In: Essential Medical Statistics. Oxford, UK: Blackwell Science Ltd; 2003. p. 249-62.
  21. Ely JW, Dawson JD, Lemke JH, Rosenberg J. An introduction to time-trend analysis. Infect Control Hosp Epidemiol. 1997;18(4):267–74. doi:.
  22. Bundesamt für Statistik. Medizinische Statistik der Krankenhäuser - Detailkonzept 1997. Neuchâtel: Bundesamt für Statistik, Sektion Gesundheit; 2005 [cited 2018 June 19]. Available from:
  23. Bundesamt für Gesundheit (BAG). Qualitätsindikatoren der Schweizer Akutspitäler. [cited 2018 Jun 19]. Available from:
  24. Bundesamt für Gesundheit BAG. SDuS. Referenzdaten für die Risikoadjustierung - CH-IQI Version 4.0 (ZIP, de fr it). Qualitätsindikatoren der Schweizer Akutspitäler 2013. 2015 [cited 2018 Jan 17]. Available from:
  25. Bundesamt für Gesundheit BAG. SDuS. Referenzdaten für die Risikoadjustierung - CH-IQI Version 4.0 (ZIP, de fr it). Qualitätsindikatoren der Schweizer Akutspitäler 2014. 2014 [cited 2018 Jan 16]. Available from:
  26. BAG. CH-IQI - Swiss Inpatient Quality Indicators. Spezifikationen Version 4.0. 2016 [cited 2018 Jan 18]. Available from:
  27. Smilowitz NR, Gupta N, Ramakrishna H, Guo Y, Berger JS, Bangalore S. Perioperative major adverse cardiovascular and cerebrovascular events associated with noncardiac surgery. JAMA Cardiol. 2017;2(2):181–7. doi:.
  28. Massarweh NN, Kougias P, Wilson MA. Complications and failure to rescue after inpatient noncardiac surgery in the veterans affairs health system. JAMA Surg. 2016;151(12):1157–65. doi:.
  29. Bundesamt für Gesundheit BAG. Positive Bilanz bei der Planung der hochspezialisierten Medizin. Bern: Bundesamt für Gesundheit BAG; 2016 [cited 2018 May 11]. Available from:
  30. Fügi M. Personal communication: Assignment of “HSM” fields, publication of decisions (in “Bundesblatt”). Bern: Swiss Conference of Cantonal Health Directors (GDK); April 12, 2018.
  31. GDK / CDS. Schweizerische Konferenz der kantonalen Gesundheitsdirektorinnen und -direktoren. Hochspezialisierte Medizin. 2018 [cited 2018 May 11]. Available from:
  32. StataCorp. Stata reference manual release 14. College Station, TX: Stata Press; 2015 [cited 2017 June 20]. Available from:
  33. Cox NJ, Wang L, Buis M. Re: st: RE: RE: generating blank observations. College Station, TX: StataCorp LLC; 2017 [cited 2017 June 25]. Available from.
  34. Cox NJ. Stata tip 17: filling in the gaps. Stata J. 2005;5(1):135–6. doi:.
  35. Kirkwood BR, Sterne JAC. Standardization. In: Essential medical statistics. Oxford: Blackwell Science Ltd.; 2003. p. 263-71.
  36. Coviello E, Consonni D, Buzzoni C, Mensi C. Distrate - Directly standardized rates with improved confidence intervals. In: StataCorp. Stata reference manual release 14. College Station, TX: Stata Press; 2015. p. 522-41, [cited 2017 June 20]. Available from:
  37. Consonni D, Coviello E, Buzzoni C, Mensi C. A command to calculate age-standardized rates with efficient interval estimation. Stata J. 2012;12(4):688–701. doi:.
  38. Dobson AJ, Kuulasmaa K, Eberle E, Scherer J. Confidence intervals for weighted sums of Poisson parameters. Stat Med. 1991;10(3):457–62. doi:.
  39. Cox NJRE. overlay bar and line graphs in STATA. 2011 [cited 2018 July 12]. Available from:
  40. Mitchell MN. A Visual Guide to Stata Graphics. College Station, Texas: Stata Press; 2012.
  41. Selvaggi G, Bellringer J. Gender reassignment surgery: an overview. Nat Rev Urol. 2011;8(5):274–82. doi:.
  42. Brown JA, Wilson TM. Benign prostatic hyperplasia requiring transurethral resection of the prostate in a 60-year-old male-to-female transsexual. Br J Urol. 1997;80(6):956–7. doi:.
  43. Kristensen SD, Knuuti J, Saraste A, Anker S, Bøtker HE, Hert SD, et al., Authors/Task Force Members. 2014 ESC/ESA Guidelines on non-cardiac surgery: cardiovascular assessment and management: The Joint Task Force on non-cardiac surgery: cardiovascular assessment and management of the European Society of Cardiology (ESC) and the European Society of Anaesthesiology (ESA). Eur Heart J. 2014;35(35):2383–431. doi:.
  44. Fleisher LA, Fleischmann KE, Auerbach AD, Barnason SA, Beckman JA, Bozkurt B, et al. 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014;130(24):2215–45. doi:.
  45. Kolh P, De Hert S, De Rango P. The concept of risk assessment and being unfit for surgery. Eur J Vasc Endovasc Surg. 2016;51(6):857–66. doi:.
  46. Boyd O, Jackson N. How is risk defined in high-risk surgical patient management? Crit Care. 2005;9(4):390–6. doi:.
  47. van Zaane B, van Klei WA, Buhre WF, Bauer P, Boerma EC, Hoeft A, et al.; European Surgical Outcomes Study (EuSOS) group for the Trials groups of the European Society of Intensive Care Medicine and the European Society of Anaesthesiology. Nonelective surgery at night and in-hospital mortality: Prospective observational data from the European Surgical Outcomes Study. Eur J Anaesthesiol. 2015;32(7):477–85. doi:.
  48. Nimptsch U, Krautz C, Weber GF, Mansky T, Grützmann R. Nationwide in-hospital mortality following pancreatic surgery in Germany is higher than anticipated. Ann Surg. 2016;264(6):1082–90. doi:.
  49. Raymond DP, Seder CW, Wright CD, Magee MJ, Kosinski AS, Cassivi SD, et al. Predictors of major morbidity or mortality after resection for esophageal cancer: a society of thoracic surgeons general thoracic surgery database risk adjustment model. Ann Thorac Surg. 2016;102(1):207–14. doi:.
  50. Haynes AB, Weiser TG, Berry WR, Lipsitz SR, Breizat AH, Dellinger EP, et al.; Safe Surgery Saves Lives Study Group. A surgical safety checklist to reduce morbidity and mortality in a global population. N Engl J Med. 2009;360(5):491–9. doi:.
  51. StataCorp. Poisson — Poisson regression. In: StataCorp. Stata reference manual release 14. College Station, TX: Stata Press; 2015. p. 1880-9; [cited 2017 June 20]. Available from:
  52. StataCorp. Pctile — Create variable containing percentiles. In: StataCorp. Stata reference manual release 14. College Station, TX: Stata Press; 2015. p. 513-24; [cited 2017 June 20]. Available from:
  53. Reif J. REGSAVE: Stata module to save regression results to a Stata-formatted dataset. Boston, MA: Boston College Department of Economics; 2016; [cited 2017 June 29]. Available from:
  54. Reif J. Storing, analyzing, and presenting Stata output. 5 ed. Boston, MA: Stata Users Group; 2010; [cited 2017 June 29]. Available from:
  55. Federal Statistical Office (FSO). Junker C. Cause of death statistic - Death and its main causes in Switzerland, 2014 [cited 2017 June 29]. Available from:
  56. Vandenbroucke JP, von Elm E, Altman DG, Gøtzsche PC, Mulrow CD, Pocock SJ, et al.; STROBE Initiative. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): explanation and elaboration. PLoS Med. 2007;4(10):e297. doi:.
  57. Thommen D, Weissenberger N, Schuetz P, Mueller B, Reemts C, Holler T, et al. Head-to-head comparison of length of stay, patients’ outcome and satisfaction in Switzerland before and after SwissDRG-Implementation in 2012 in 2012: an observational study in two tertiary university centers. Swiss Med Wkly. 2014;144:w13972. doi:.
  58. Lass P, Lilholt J, Thomsen L, Lundbye-Christensen S, Enevoldsen H, Simonsen OH. Kvaliteten af diagnose- og procedurekodning i Ortopaedkirurgi Nordjylland [The quality of diagnosis and procedure coding in Orthopaedic surgery Northern Jutland]. Ugeskr Laeger. 2006;168(48):4212–5. Article in Danish.
  59. Nymark T, Thomsen K, Röck ND. [Diagnosis and procedure coding in relation to the DRG system]. Ugeskr Laeger. 2003;165(3):207–9.
  60. Klaus B, Ritter A, Grosse Hülsewiesche H, Beyrle B, Euler HU, Fender H, et al. Untersuchung zur Qualität der Kodierungen von Diagnosen und Prozeduren unter DRG-Bedingungen [Study of the quality of codification of diagnoses and procedures under DRG conditions]. Gesundheitswesen. 2005;67(1):9–19. Article in German. doi:.
  61. Franz D, Kaufmann M, Siebert CH, Windolf J, Roeder N. Unfallchirurgie und Orthopädie im G-DRG-System 2007 [Orthopedic and trauma surgery in the German DRG System 2007]. Unfallchirurg. 2007;110(3):270–80. Article in German. doi:.
  62. Nimptsch U. Disease-specific trends of comorbidity coding and implications for risk adjustment in hospital administrative data. Health Serv Res. 2016;51(3):981–1001. doi:.
  63. Wasserfallen JB, Zufferey J. Financial impact of introducing the Swiss-DRG reimbursement system on potentially avoidable readmissions at a university hospital. Swiss Med Wkly. 2015;145:w14097. doi:.
  64. Chok L, Bachli EB, Steiger P, Bettex D, Cottini SR, Keller E, et al. Effect of diagnosis related groups implementation on the intensive care unit of a Swiss tertiary hospital: a cohort study. BMC Health Serv Res. 2018;18(1):84. doi:.
  65. Bundesamt für Statistik BfS. Gesundheitsversorgungsstatistik – Ambulante Statistiken im Projekt MARS (Modules Ambulatoires des Relevés sur la Santé). 2017 [cited 2018 Dec 11]. Available from:
  66. Bundesamt für Statistik (BfS). Statistiken der ambulanten Gesundheitsversorgung (MARS). [cited 2018 Dec 11]. Available from:
  67. Sammon JD, Pucheril D, Abdollah F, Varda B, Sood A, Bhojani N, et al. Preventable mortality after common urological surgery: failing to rescue? BJU Int. 2015;115(4):666–74. doi:.
  68. Moawad G, Liu E, Song C, Fu AZ. Movement to outpatient hysterectomy for benign indications in the United States, 2008-2014. PLoS One. 2017;12(11):e0188812. doi:.
  69. Aynardi M, Post Z, Ong A, Orozco F, Sukin DC. Outpatient surgery as a means of cost reduction in total hip arthroplasty: a case-control study. HSS J. 2014;10(3):252–5. doi:.
  70. Gignoux B, Gosgnach M, Lanz T, Vulliez A, Blanchet MC, Frering V, et al. Short-term outcomes of ambulatory colectomy for 157 consecutive patients. Ann Surg. 2018. [Epub ahead of print.] doi:.
  71. Leeder PC, Matthews T, Krzeminska K, Dehn TC. Routine day-case laparoscopic cholecystectomy. Br J Surg. 2004;91(3):312–6. doi:.
  72. Talsma AK, Lingsma HF, Steyerberg EW, Wijnhoven BP, Van Lanschot JJ. The 30-day versus in-hospital and 90-day mortality after esophagectomy as indicators for quality of care. Ann Surg. 2014;260(2):267–73. doi:.
  73. Rydenfelt K, Engerström L, Walther S, Sjöberg F, Strömberg U, Samuelsson C. In-hospital vs. 30-day mortality in the critically ill - a 2-year Swedish intensive care cohort analysis. Acta Anaesthesiol Scand. 2015;59(7):846–58. doi:.
  74. Damhuis RA, Wijnhoven BP, Plaisier PW, Kirkels WJ, Kranse R, van Lanschot JJ. Comparison of 30-day, 90-day and in-hospital postoperative mortality for eight different cancer types. Br J Surg. 2012;99(8):1149–54. doi:.
  75. Kirksey M, Chiu YL, Ma Y, Della Valle AG, Poultsides L, Gerner P, et al. Trends in in-hospital major morbidity and mortality after total joint arthroplasty: United States 1998-2008. Anesth Analg. 2012;115(2):321–7. doi:.
  76. Hogan H, Zipfel R, Neuburger J, Hutchings A, Darzi A, Black N. Avoidability of hospital deaths and association with hospital-wide mortality ratios: retrospective case record review and regression analysis. BMJ. 2015;351:h3239. doi:.
  77. Finks JF, Osborne NH, Birkmeyer JD. Trends in hospital volume and operative mortality for high-risk surgery. N Engl J Med. 2011;364(22):2128–37. doi:.
  78. Kim SP, Boorjian SA, Shah ND, Karnes RJ, Weight CJ, Moriarty JP, et al. Contemporary trends of in-hospital complications and mortality for radical cystectomy. BJU Int. 2012;110(8):1163–8. doi:.
  79. Hounsome LS, Verne J, McGrath JS, Gillatt DA. Trends in operative caseload and mortality rates after radical cystectomy for bladder cancer in England for 1998-2010. Eur Urol. 2015;67(6):1056–62. doi:.
  80. Kelly DA, Pedersen S, Tosenovsky P, Sieunarine K. Major lower limb amputation: outcomes are improving. Ann Vasc Surg. 2017;45:29–34. doi:.
  81. Güller U, Warschkow R, Ackermann CJ, Schmied B, Cerny T, Ess S. Lower hospital volume is associated with higher mortality after oesophageal, gastric, pancreatic and rectal cancer resection. Swiss Med Wkly. 2017;147:w14473. doi:.
  82. Maggard-Gibbons M. Use of report cards and outcome measurements to improve safety of surgical care: American College of Surgeons National Quality Improvements Program (NEW). In: Shekelle PG, Wachter RM, Pronovost PJ, editorsMaking health care safer II: an updated critical analysis of the evidence for patient safety practices Comparative effectiveness review no 211. Rockville, MD: Agency for Healthcare Research and Quality; 2013. p. 140-57; [cited 2018 September 15]. Available from.
  83. Shekelle PG, Pronovost PJ, Wachter RM, McDonald KM, Schoelles K, Dy SM, et al. The top patient safety strategies that can be encouraged for adoption now. Ann Intern Med. 2013;158(5 Pt 2):365–8. doi:.
  84. Yuen WC, Wong K, Cheung YS, Lai PB. Reduction of operative mortality after implementation of surgical outcomes monitoring and improvement programme by Hong Kong Hospital Authority. Hong Kong Med J. 2018;24(2):137–44. doi:.

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