Background: Pharmacists have an increasing role as part of the emergency department (ED) team. However, the impact of ED-based pharmacy interventions on the quality use of medicines has not been well characterised.

Objective: This systematic review aimed to synthesise evidence from studies examining the impact of interventions provided by pharmacists on the quality use of medicines in adults presenting to ED.

Methods: A systematic literature search was conducted in MEDLINE, EMBASE and CINAHL. Two independent reviewers screened titles/abstracts and reviewed full texts. Studies that compared the impact of interventions provided by pharmacists with usual care in ED and reported medication-related primary outcomes were included. Cochrane Risk of Bias-2 and Newcastle-Ottawa tools were used to assess the risk of bias. Summary estimates were pooled using random-effects meta-analysis, along with sensitivity and sub-group analyses.

Results: Thirty-one studies involving 13 242 participants were included. Pharmacists were predominantly involved in comprehensive medication review, advanced pharmacotherapy assessment, staff and patient education, identification of medication discrepancies and drug-related problems, medication prescribing and co-prescribing, and medication preparation and administration. The activities reduced the number of medication errors by a mean of 0.33 per patient (95% CI -0.42 to -0.23, I2=51%) and the proportion of patients with at least one error by 73% (risk ratio (RR)=0.27, 95% CI 0.19 to 0.40, I2=85.3%). The interventions were also associated with more complete and accurate medication histories, increased appropriateness of prescribed medications by 58% (RR=1.58, 95% CI 1.21 to 2.06, I2=95%) and quicker initiation of time-critical medications.

Conclusion: The evidence indicates improved quality use of medicines when pharmacists are included in ED care teams.