[Incidence of adverse events in hospitals. A retrospective study of medical records]

Abstract

Introduction: Over the past decade a number of studies on the incidence and preventability of adverse events in the health care have been published in the US, Australia and the UK. So far no similar study has been performed in Denmark. In order to determine whether foreign findings could be generalised to Danish health care, a pilot study on adverse events was carried out in Danish acute care hospitals.

Method: Chart reviews were carried out on 1.097 acute care hospital admissions, sampled from the central Danish National Patient Register. The sample was truly proportional with no over-sampling of high-risks groups. Chart reviews was done in 17 different acute care hospitals, reviewing between 20 and 204 admissions per hospital. Adverse events was identified using a three-step procedure: 1) Nurse screening by 18 criteria identifying high-risk groups. 2) Independent reviews by pairs of consultants. 3) In case of disagreement between second step consultants, two additional independent reviews was performed by new consultants (internist and surgeon) followed by conference. All chart reviews were performed independent of medical specialty. All nurses and doctors were senior and experienced clinicians.

Results: In 114 admissions 176 Adverse Events (AEs) were identified. The prevalence of admissions with adverse events were 9.0% of all admissions. Preventability of adverse events was found in 46 of admissions (40.4% of AEs). The adverse events caused on average a 7.0 days prolonged hospital stay. Most adverse events resulted in minor, transient disabilities. Permanent disability or death in relation to adverse event were recorded in 30 admissions.

Discussion: The findings from the Danish Adverse Event Study are similar to the results found in Australia, United Kingdom and the United States. It is therefore recommended that further Danish research, is directed towards high-risk groups focussing on narratives and intervention and towards research in primary health care.