Professor Yaseen Hayajneh Website

Adverse Events (Medical Errors)


Adverse Events are ‘instances which indicate or may indicate that a patient has received poor quality care’ [2].  An AE is defined as ‘an injury that was caused by medical management (rather than the underlying disease) and that prolonged the hospitalization, produced a disability at the time of discharge, or both’ [3].

The Quality in Australia Health Care Study revealed that 16.6% of admissions were associated with an ‘adverse event’, which resulted in either disability or a longer hospital stay for the patient and was caused by health-care management. In 13.7% of these cases the disability was permanent and in 4.9% the patient died [15].  In UK, a study found that 10.8% of admitted patients experienced an AE [16].

In UK and Australia, about half of AE cases were considered preventable [15, 16]. The Hospitals for Europe’s Working Party on Quality Care in Hospitals estimated in 2000 that 10% of patients in European hospitals suffer from preventable harm and adverse effects related to his or her care [17]. An Australian study found that 17% of postoperative cases in a teaching hospital experienced at least one serious AE and that 7% of postoperative cases ended in the death of patient [18]. In Canada, it is estimated that the overall incidence rate of AEs is 7.5% of hospital admissions and that 37% of these AEs are potentially preventable [19].

In France, the incidence of AEs was estimated at 6.6 per 1000 hospital days in 2004, from which 24.1% were Hospital Acquired Infections.20 In Germany, the Dutch Patient Safety Research Program showed that AEs affect 5.7% of patients in Dutch hospitals [21].


  1. Adverse Events: Unreported Hospital Errors (10:11)
  2. Adverse Events in Hospitals, in Arabic (8:57)
  3. Adverse Events in Yemen, media report (5:08)



2 Walshe K, Bennett J, Ingram D. Using adverse events in health care quality improvement: Results from a British acute hospital. International Journal of Health Care Quality Assurance 1995; 8: 7–14.

3 Brennan T, Leape L, Laird N et al. Incidence of adverse events and negligence in hospitalized patients: Results of the Harvard Medical Practice Study I. Quality and Safety in Health Care 2004; 13: 145–152.

15 Wilson R, Runciman W, Gibberd R, Harrison B, Newby L,Hamilton J. The Quality in Australia Health Care Study. The Medical Journal of Australia 1995; 163: 458–476.

16 Vincent C, Neale G, Woloshcynowych M. Adverse events in British hospitals: preliminary retrospective record review. BMJ 2001; 322: 517–519.

17 WHO. Quality of Care: Patient Safety: Report by the Secretariat. 2002. Available from URL: Accessed 12 June 2008.

18 Bellomo R, Goldsmith D, Russell S, Uchino S. Postoperative serious adverse events in a teaching hospital: A prospective study. The Medical Journal of Australia 2002; 176: 216–218.

19 Baker G, Norton P, Flintoft V et al. The Canadian Adverse Events Study: The incidence of adverse events among hospital patients in Canada. Canadian Medical Association Journal 2004; 170: 1678–1686.

21 Zegers M, de Bruijne M, Wagner C, Groenewegen P, Waaijman R, van der Wal G. Design of a retrospective patient record study on the occurrence of adverse events among patients in Dutch hospitals. BMC Health Services Research 2007; 25: 7–27.

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January 27th, 2012 at 8:18 am