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The prevalence of medication-related adverse events in inpatients—a systematic review and meta-analysis



Adverse drug events (ADEs) have been internationally recognized as a major threat to patient safety. The purpose of this study was to conduct a meta-analysis focusing on inpatient ADEs in the Western World to provide better estimate of the current state of medication safety in these countries.


The studies for meta-analysis were identified through electronic search in Cochrane, Scopus, Medline, and Web of science databases. Included articles focused on adult inpatient ADEs, had commonly accepted definition for ADE, and were conducted between 2000 and 2016. Disease or ADE-specific studies were excluded. Meta-analysis was conducted on the prevalence of inpatient ADEs and fatal adverse drug reactions (FADRs).


The pooled estimate of the prevalence of inpatient ADEs was formed by 46,626 patient records included in 9 articles. Inpatient ADE prevalence was 19 and 32.3% of these ADEs were assessed preventable (MD 28.6%, SD 22.6%). Three articles including 3385 patients focused on inpatient FADRs, but the pooled estimate of this was disregarded due to low number and high heterogeneity of the included studies.


ADEs are estimated to affect 19% of inpatients during hospitalization. Most of the ADEs are moderate in severity causing no permanent harm to the patient. Only a small amount of ADEs cause inpatient deaths, but in this meta-analysis, however, we were unable to give direct estimate of the prevalence.

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M.Sc. Raija Heino is greatly acknowledged for her help with electronic database searches together with M.Sc. (Pharm) Sanjay Patel for his expert language revision.


No funding was received for the conduct or for the preparation of this study.

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Correspondence to Outi Laatikainen.

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Laatikainen, O., Miettunen, J., Sneck, S. et al. The prevalence of medication-related adverse events in inpatients—a systematic review and meta-analysis. Eur J Clin Pharmacol 73, 1539–1549 (2017).

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  • Adverse drug events
  • Drug safety
  • Clinical pharmacology
  • Pharmacoepidemiology