Meta-analysis of recent studies on patients admitted to hospital due to adverse drug effects

The use of drugs has expanded during the previous decade. However, earlier studies on patients admitted for adverse drugs effects (ADEs) have been heterogeneous. The objectives of this study were to assess the number of recent admissions to hospital due to ADEs and to assess the degree of heterogeneity in recent studies. Prospective studies published in the past decade were therefore pooled and compared with the pooled results from earlier studies. The pooled overall percentage in recent studies (n = 20) was 5.4% (5.0 - 5.8) and this did not significantly differ from that in the earlier studies (n = 21, pooled percentage 4.7%, 3.1 - 6.2). The studies were clinically very heterogeneous with percentages of ADEs between 3.4 and 33.2%. The nature of the patient group could be held largely responsible for the clinical heterogeneity observed.