Association of Pharmacist Interventions With Adverse Drug Events and Potential Adverse Drug Events.

Background: Adverse drug events (ADEs) are a frequent cause of injury in patients. Our aim was to assess whether pharmacist interventions compared with no pharmacist intervention results in reduced ADEs and potential adverse drug events (PADEs).

Methods: We searched MEDLINE, Embase, and two other databases through September 19, 2022 for any RCT assessing the effect of a pharmacist intervention compared with no pharmacist intervention and reporting on ADEs or PADEs. The risk of bias was assessed using the Cochrane tool for RCTs. A random-effects model was used to pool summary results from individual RCTs.

Results: Fifteen RCTs met the inclusion criteria. The pooled results showed a statistically significant reduction in ADE associated with pharmacist intervention compared with no pharmacist intervention (RR = 0.86; [95% CI 0.80-0.94]; p = 0.0005) but not for PADEs (RR = 0.79; [95% CI 0.47-1.32]; p = 0.37). The heterogeneity was insignificant (I² = 0%) for ADEs and substantial (I² = 77%) for PADEs. Patients receiving a pharmacist intervention were 14% less likely for ADE than those who did not receive a pharmacist intervention. The estimated number of patients needed to prevent one ADE across all patient locations was 33.

Conclusions: To our knowledge, this is the first systematic review and meta-analysis of RCTs seeking to understand the association of pharmacist interventions with ADEs and PADEs. The risk of having an ADE is reduced by a seventh for patients receiving a pharmacist care intervention versus no such intervention. The estimated number of patients needed to be followed across all patient locations to prevent one preventable ADE across all patient locations is 33.