The incidence of adverse events in Swedish hospitals: a retrospective medical record review study

Int J Qual Health Care. 2009 Aug;21(4):285-91. doi: 10.1093/intqhc/mzp025. Epub 2009 Jun 25.


Objectives: To estimate the incidence, nature and consequences of adverse events and preventable adverse events in Swedish hospitals.

Design: A three-stage structured retrospective medical record review based on the use of 18 screening criteria.

Setting: Twenty-eight Swedish hospitals. Population A representative sample (n = 1967) of the 1.2 million Swedish hospital admissions between October 2003 and September 2004.

Main outcome measures: Proportion of admissions with adverse events, the proportion of preventable adverse events and the types and consequences of adverse events.

Results: In total, 12.3% (n = 241) of the 1967 admissions had adverse events (95% CI, 10.8-13.7), of which 70% (n = 169) were preventable. Fifty-five percent of the preventable events led to impairment or disability, which was resolved during the admission or within 1 month from discharge, another 33% were resolved within 1 year, 9% of the preventable events led to permanent disability and 3% of the adverse events contributed to patient death. Preventable adverse events led to a mean increased length of stay of 6 days. Ten of the 18 screening criteria were sufficient to detect 90% of the preventable adverse events. When extrapolated to the 1.2 million annual admissions, the results correspond to 105,000 preventable adverse events (95% CI, 90,000-120,000) and 630,000 days of hospitalization (95% CI, 430,000-830,000).

Conclusions: This study confirms that preventable adverse events were common, and that they caused extensive human suffering and consumed a significant amount of the available hospital resources.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Child, Preschool
  • Female
  • Hospital Administration / statistics & numerical data*
  • Humans
  • Incidence
  • Infant
  • Infant, Newborn
  • Male
  • Medical Errors / statistics & numerical data*
  • Middle Aged
  • Quality Assurance, Health Care
  • Quality Indicators, Health Care / statistics & numerical data*
  • Retrospective Studies
  • Safety Management
  • Sweden
  • Young Adult