Incidence of medication-related harm in older adults following hospital discharge: a systematic review

Objectives To determine the incidence, severity, preventability and risk factors for medication-related harm (MRH)in community-dwelling older adults following hospital discharge. Design: Systematic review Setting: A search of Medline, EMBASE, CINAHL, and the Cochrane Library was undertaken without time restrictions Participants Older adults (average age ?65 years) participating in observational studies investigating adverse drug reactions (ADR) or adverse drug events (ADE)post-discharge within a defined follow-up period Measurements The abstracts of all articles were initially screened by one author to exclude obviously irrelevant articles. The remaining articles were independently screened by two authors for inclusion. Data extraction,including study characteristics, MRH incidence and risk factors, and, critical appraisal was performed by two authors independently, and verified by a third reviewer. Disagreements were resolved through discussion. Results Out of 584 potentially relevant articles, eight studies met our inclusion criteria; five North American and three European. Most of the included studies were of moderate quality. There was a wide range in MRH incidence, from 0.4% to 51.2% of patients, and 35% to 59% of MRH was preventable. The MRH incidence within 30 days post-discharge ranges from 167 to 500 events per 1000 patients discharged (17-51% of patients. Substantial methodological heterogeneity exists across multiple domains of the studies, including ADR and ADE definitions, characteristics of recruited populations, the follow-up duration post-discharge, and data collection. Conclusions Medication-related harm is common following hospital discharge in older adults. However, a clear understanding of the epidemiology is hampered by methodological inconsistencies between studies and a paucity of data on risk factors. There is need for international consensus on conducting and reporting MRH studies.Data from large, multicentre studies examining a range of biopsychosocial risk factors could add insight to this important area of patient safety.