OBJECTIVES: To determine the association between pharmacists’ medication counseling, and medication adherence, 30-day hospital readmission, and mortality in patents at risk of high healthcare utilization. Secondarily, to assess the association between pharmacist medication counseling and emergency department and primary care visits. The method of comparison was relative risk.

METHODS: Two researchers independently reviewed abstracts identified by the systematic review and applied inclusion criteria: a published RCT study or abstraction; pharmacist only intervention; comparison group with no pharmacist counseling; and the presence of the outcomes of interest. Three researchers abstracted data and assessed each included study for bias using Cochrane criteria. Results were compared and harmonized by consensus. GRADE and PRISMA guidelines were followed carefully. Data were pooled using the random effects model.

RESULTS: Of 62 studies meeting the inclusion criteria, 49 qualified for the meta-analysis. Almost all studies used patients at risk (like older, polypharmacy, co-morbidity) for high healthcare utilization and analyzed for more than one outcome. Pharmacist medication counseling of high-risk patients versus no pharmacist medication counseling was associated with a 30% relative risk (RR) increase in medication adherence (p = <0.01; CI⁹⁵ 1.19, 1.43); a 24% RR reduction in 30-day hospital readmission(p <0.01; CI⁹⁵ 0.58, 0.99); and a 30% RR reduction in emergency department visits (p <0.01; CI⁹⁵ 0.51, 0.96). RR reductions for primary care visits and mortality were obvious, but not statistically significant . The number needed to treat (NNT) to prevent one 30-day readmission was 4.2. For studies that measured both adherence and 30-day readmission, there was a 2.6% drop in the relative risk of 30-day readmission for every 10% increase in medication adherence.

CONCLUSIONS: There is a statistically significant and beneficial association between pharmacist medication counseling with medication adherence, 30-day hospital readmissions, and emergency department visits in patients at risk for high healthcare utilization.