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Original article

Vol. 149 No. 4546 (2019)

Describing adverse events in medical inpatients using the Global Trigger Tool

  • Nicole Grossmann
  • Franziska Gratwohl
  • Sarah N. Musy
  • Natascha M. Nielen
  • Jacques Donzé
  • Michael Simon
Cite this as:
Swiss Med Wkly. 2019;149:w20149



The purpose of the study was to describe the type, prevalence, severity and preventability of adverse events (AEs) that affected hospitalised medical patients. We used the previously developed and validated Global Trigger Tool from the Institute for Healthcare Improvement.


Using an adapted version of the Global Trigger Tool, we conducted a retrospective chart review of adult patients hospitalised in five medical wards at a university hospital in Switzerland. We reviewed a random sample of 20 patients’ charts for a total study period of 12 months (September 2016 to August 2017). Two trained nurses searched independently for triggers and possible AEs. All AEs were further validated by a senior physician. The number of triggers and AEs detected, as well as the severity and preventability of each, was assessed and analysed using descriptive statistics.


From a sample of 240 patient charts, we identified 1371 triggers and 336 AEs in 144 (60%) inpatients. This translates to an AE rate of 95.7 AEs per 1000 patient days. Most AEs (86.1%) caused temporary harm to the patient and required an intervention and/or prolonged hospitalisation. The estimated preventability of the in-hospital AEs was 29%. Healthcare-associated infections (25.8%) and neurological reactions (22.9%) were the most frequent AE types.


We found that about two thirds of patients suffered from AEs with harm during hospitalisation. It is common knowledge that AEs occur in hospitals and that they have potentially harmful consequences for patients, as well as a strong economic impact. However, to adequately prioritise patient safety interventions, it is essential to explore the nature, prevalence, severity and preventability of AEs. This is not only beneficial for the patients, but also cost effective in terms of shorter hospital stays.


  1. World Health Organization. 10 Facts on Patient Safety Geneva, 2017 [cited 2018 June 03]. Available from:
  2. Vincent C. The nature and scale of error and harm. Patient Safety. 2: Willey Blackwell, BMJ Books; 2010. p. 49–74.
  3. Health Quality & Safety Commission New Zealand. The Global Trigger Tool: A Review of the Evidence, 2013. Available from:
  4. Griffin F, Resar RK. IHI Global Trigger Tool for Measuring Adverse Events. IHI Innovation Series white paper [Internet]. 2009. Available from:
  5. Naessens JM, Campbell CR, Huddleston JM, Berg BP, Lefante JJ, Williams AR, et al. A comparison of hospital adverse events identified by three widely used detection methods. Int J Qual Health Care. 2009;21(4):301–7. doi:.
  6. de Vries EN, Ramrattan MA, Smorenburg SM, Gouma DJ, Boermeester MA. The incidence and nature of in-hospital adverse events: a systematic review. Qual Saf Health Care. 2008;17(3):216–23. doi:.
  7. O’Leary KJ, Devisetty VK, Patel AR, Malkenson D, Sama P, Thompson WK, et al. Comparison of traditional trigger tool to data warehouse based screening for identifying hospital adverse events. BMJ Qual Saf. 2013;22(2):130–8. doi:.
  8. Kjellberg J, Wolf RT, Kruse M, Rasmussen SR, Vestergaard J, Nielsen KJ, et al. Costs associated with adverse events among acute patients. BMC Health Serv Res. 2017;17(1):651. doi:.
  9. Thomas EJ, Brennan TA. Incidence and types of preventable adverse events in elderly patients: population based review of medical records. BMJ. 2000;320(7237):741–4. doi:.
  10. Hibbert PD, Molloy CJ, Hooper TD, Wiles LK, Runciman WB, Lachman P, et al. The application of the Global Trigger Tool: a systematic review. Int J Qual Health Care. 2016;28(6):640–9. doi:.
  11. Halfon P, Staines A, Burnand B. Adverse events related to hospital care: a retrospective medical records review in a Swiss hospital. Int J Qual Health Care. 2017;29(4):527–33. doi:.
  12. Patientensicherheit Schweiz. Ein Public Health-Problem - Facts & Figures Zürich: Stiftung für Patientensicherheit Schweiz; n.d. [cited 2018 June 03]. Available from:
  13. Swissnoso. SSI Surveillance: Verein Swissnoso. Nationales Zentrum für Infektionsprävention; 2018 [cited 2018 June 03]. Available from:
  14. Agency for Healtcare Research and Quality (AHRQ). Patient Safety Indicators Rockville, MD, USA: Agency for Healtcare Research and Quality 2017 [cited 2018 June 03]. Available from:
  15. Rutberg H, Borgstedt Risberg M, Sjödahl R, Nordqvist P, Valter L, Nilsson L. Characterisations of adverse events detected in a university hospital: a 4-year study using the Global Trigger Tool method. BMJ Open. 2014;4(5):e004879. doi:.
  16. Kennerly DA, Kudyakov R, da Graca B, Saldaña M, Compton J, Nicewander D, et al. Characterization of adverse events detected in a large health care delivery system using an enhanced global trigger tool over a five-year interval. Health Serv Res. 2014;49(5):1407–25. doi:.
  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. Murff HJ, Patel VL, Hripcsak G, Bates DW. Detecting adverse events for patient safety research: a review of current methodologies. J Biomed Inform. 2003;36(1-2):131–43. doi:.
  19. Insel Gruppe AG. Bettenkennzahlen. In: Klinik für Allgemeine Innere Medizin, editor. Bern: Inselspital, Universitätsspital Bern; 2016.
  20. Insel Gruppe AG. Die Universitätsklinik für Allgemeine Innere Medizin Bern: Inselspital; (n.d) [cited 2018 June 01]. Available from:
  21. Soop M, Fryksmark U, Köster M, Haglund B. The incidence of adverse events in Swedish hospitals: a retrospective medical record review study. Int J Qual Health Care. 2009;21(4):285–91. doi:.
  22. Bothe J, von Hielmcrone C. Aktives Messinstrument der Patientensicherheit -das IHI Global Trigger Tool. Stärkung der Patientensicherheit zwischen Dänemark und Deutschland [Internet]. 2009 [cited 2018 June 02]. Available from:
  23. National Coordinating Council for Medication Error Reporting and Prevention (NCC MERP). Types of medication errors 2001 [cited 2019 June 17]. Available from:
  24. R Development Core Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing Vienna, Austria2008. Available from:
  25. Winston C. Interrater reliability n.a. [cited 2018 June 01]. Available from:
  26. Polit DF, Beck CT. Nursing research: generating and assessing evidence for nursing practice. 9th ed. Philadelphia: Lippincott, Williams & Wilkins; 2012. 802 S. p.
  27. Deutsches Institut für Medizinische Dokumentation und Information D. ICD-10-GM. Version 2018, Internationale statistische Klassifikation der Krankheiten und verwandter Gesundheitsprobleme 10. Revision German Modification. Version 2016 Köln: Bundesministeriums für Gesundheit (BMG); 2017 [cited 2018 June 03]. Available from:
  28. Musy SN, Ausserhofer D, Schwendimann R, Rothen HU, Jeitziner MM, Rutjes AW, et al. Trigger Tool-Based Automated Adverse Event Detection in Electronic Health Records: Systematic Review. J Med Internet Res. 2018;20(5):e198. doi:.
  29. Kennerly DA, Saldaña M, Kudyakov R, da Graca B, Nicewander D, Compton J. Description and evaluation of adaptations to the global trigger tool to enhance value to adverse event reduction efforts. J Patient Saf. 2013;9(2):87–95. doi:.
  30. Mortaro A, Moretti F, Pascu D, Tessari L, Tardivo S, Pancheri S, et al. Adverse Events Detection Through Global Trigger Tool Methodology: Results From a 5-Year Study in an Italian Hospital and Opportunities to Improve Interrater Reliability. J Patient Saf. 2017. Published online June 10, 2017. doi:.
  31. Good VS, Saldaña M, Gilder R, Nicewander D, Kennerly DA. Large-scale deployment of the Global Trigger Tool across a large hospital system: refinements for the characterisation of adverse events to support patient safety learning opportunities. BMJ Qual Saf. 2011;20(1):25–30. doi:.
  32. Senn L, Sommerstein R, Troillet N. Prävention Healthcare-assoziierter Infektionen im Jahr 2017. Swiss Med Forum. 2017;17(45):974–8. doi:.
  33. Inouye SK. A practical program for preventing delirium in hospitalized elderly patients. Cleve Clin J Med. 2004;71(11):890–6. doi:.
  34. Woo KY, Beeckman D, Chakravarthy D. Management of Moisture-Associated Skin Damage: A Scoping Review. Adv Skin Wound Care. 2017;30(11):494–501. doi:.
  35. Suarez C, Menendez MD, Alonso J, Castaño N, Alonso M, Vazquez F. Detection of adverse events in an acute geriatric hospital over a 6-year period using the Global Trigger Tool. J Am Geriatr Soc. 2014;62(5):896–900. doi:.
  36. Mevik K, Griffin FA, Hansen TE, Deilkås ET, Vonen B. Does increasing the size of bi-weekly samples of records influence results when using the Global Trigger Tool? An observational study of retrospective record reviews of two different sample sizes. BMJ Open. 2016;6(4):e010700. doi:.
  37. Nilsson L, Risberg MB, Montgomery A, Sjödahl R, Schildmeijer K, Rutberg H. Preventable adverse events in surgical care in Sweden: A nationwide review of patient notes. Medicine (Baltimore). 2016;95(11):e3047. doi:.
  38. Kurutkan MN, Usta E, Orhan F, Simsekler MC. Application of the IHI Global Trigger Tool in measuring the adverse event rate in a Turkish healthcare setting. Int J Risk Saf Med. 2015;27(1):11–21. doi:.
  39. von Plessen C, Kodal AM, Anhøj J. Experiences with global trigger tool reviews in five Danish hospitals: an implementation study. BMJ Open. 2012;2(5):e001324. doi:.
  40. Patientensicherheit Schweiz. Critical Incident Reporting & Reacting NETwork Zürich: Stiftung für Patientensicherheit; n.d. [cited 2018 June 03]. Available from:
  41. Patientensicherheit Schweiz. Morbiditäts- und Mortalitätskonferenzen (MoMo) Zürich: Stiftung für Patientensicherheit; n.d [cited 2018 June 02]. Available from:
  42. Li Q, Melton K, Lingren T, Kirkendall ES, Hall E, Zhai H, et al. Phenotyping for patient safety: algorithm development for electronic health record based automated adverse event and medical error detection in neonatal intensive care. J Am Med Inform Assoc. 2014;21(5):776–84. doi:.
  43. Menendez ME, Janssen SJ, Ring D. Electronic health record-based triggers to detect adverse events after outpatient orthopaedic surgery. BMJ Qual Saf. 2016;25(1):25–30. doi:.
  44. Wong BM, Dyal S, Etchells EE, Knowles S, Gerard L, Diamantouros A, et al. Application of a trigger tool in near real time to inform quality improvement activities: a prospective study in a general medicine ward. BMJ Qual Saf. 2015;24(4):272–81. doi:.

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