Half the side effects from medicine are unnecessary
Side effects from medicines cause great suffering and constitute a heavy financial burden for the healthcare industry. A global study lead by Linköping University has now shown that half of all side effects can be prevented.
The result, based on 24 original studies of a total of 73,000 patients from four continents was published in the scientific online journal PLoS One.
“This is the first compilation of such a large number of patients. The portion of preventable side effects is somewhat higher that expected,” says Staffan Hägg, professor of Clinical Pharmacology at Linköping University.
The project’s collaboration between LiU and the Nordic School of Public Health (NHV), involved Katja Hakkarainen and Khadija Hedna examination of 22 scientific articles including results from Asia, Australia, Europe, and North America. Among the 48,797 adult emergency patients, 2% suffered from “unnecessary” side effects from medicines. Of all side effects in this group, 52% could have been prevented. The corresponding numbers among 24,128 inpatients were 1.6% and 45%, respectively.
The studies reviewed all used recognised definitions of side effects from medicine. A side effect was considered possible to prevent when something deviated from the standard, for example when the incorrect dose of the medicine was administered, or the patient was not properly supervised.
“Our work describes the magnitude of the problem. The next step is to look at which measures can reduce the portion of preventable side effects in a cost-effective way,” Hägg says.
By the autumn of 2012, he expects unique data from a population-based study of 5,000 patients in Östergötland, East Sweden, which could form the foundation for these kinds of assessments.
Article: Percentage of patients with preventable adverse drug reactions and preventability of adverse drug reactions – a meta-analysis by Katja M. Hakkarainen, Khadija Hedna, Max Petzold, and Staffan Hägg. PLoS One 7(3), 15 March 2012.
Contact: Staffan Hägg, 010-1034422,
Last updated: 2015-06-03