Article Text

Using prospective clinical surveillance to identify adverse events in hospital
  1. Alan J Forster1,2,3,4,
  2. Jim R Worthington1,
  3. Steven Hawken3,4,
  4. Michael Bourke5,
  5. Fraser Rubens5,
  6. Kaveh Shojania1,2,3,6,
  7. Carl van Walraven1,2,3,4
  1. 1The Ottawa Hospital, Ottawa, Canada
  2. 2Department of Medicine, University of Ottawa, Ottawa, Canada
  3. 3Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada
  4. 4Institute for Clinical Evaluative Sciences, Ottawa, Canada
  5. 5University of Ottawa Heart Institute, Ottawa, Canada
  6. 6Department of Medicine, Sunnybrook Health Sciences Centre and University of Toronto Centre for Patient Safety, Toronto, Canada
  1. Correspondence to Dr Alan J Forster, Ottawa Hospital, Civic Campus, 1053 Carling Avenue, Administrative Services Building 1, Ottawa, ON K1Y 4E9, Canada; aforster{at}


Background To improve patient safety, organisations must systematically measure avoidable harms. Clinical surveillance—consisting of prospective case finding and peer review—could improve identification of adverse events (AEs), preventable AEs and potential AEs. The authors sought to describe and compare findings of clinical surveillance on four clinical services in an academic hospital.

Methods Clinical surveillance was performed by a nurse observer who monitored patients for prespecified clinical events and collected standard information about each event. A multidisciplinary, peer-review committee rated causation for each event. Events were subsequently classified in terms of severity and type.

Results The authors monitored 1406 patients during their admission to four hospital services: Cardiac Surgery Intensive Care (n=226), Intensive Care (n=211), General Internal Medicine (n=453) and Obstetrics (n=516). The authors detected 245 AEs during 9300 patient days of observation (2.6 AEs per 100 patient days). 88 AEs (33%) were preventable. The proportion of patients experiencing at least one AE, preventable AE or potential AE was 13.7%, 6.1% and 5.3%, respectively. AE risk varied between services, ranging from 1.4% of Obstetrics to 11% of Internal Medicine and Intensive Care patients experiencing at least one preventable AE. The proportion of patients experiencing AEs resulting in permanent disability or death varied between services: ranging from 0.2% on Obstetrics to 4.9% on Cardiac Surgery Intensive Care. No services shared the most frequent AE type.

Conclusions Using clinical surveillance, the authors identified a high risk of AE and significant variation in AE risks and subtypes between services. These findings suggest that institutions will need to evaluate service-specific safety problems to set priorities and design improvement strategies.

  • Medical errors
  • adverse events
  • prospective surveillance
  • patient safety
  • near miss

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  • Funding This research received financial support from the Canadian Patient Safety Institute, the Canadian Institute for Health Research, the Healthcare Insurance Reciprocal of Canada, the University of Ottawa Heart Institute and the Ottawa Hospital Centre for Patient Safety.

  • Competing interests None.

  • Ethics approval Ethics approval was provided by the Ottawa Hospital Research Ethics Board.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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