Effect of a Pharmacist Intervention on Clinically Important Medication Errors After Hospital Discharge: A Randomized Trial

Study Questions:

What is the effect of a tailored pharmacist intervention on the occurrence of clinically important adverse drug events (ADEs) and medication errors after hospital discharge?


A randomized, controlled trial with concealed allocation and blinded outcome assessors was conducted in two tertiary care academic hospitals. Eligible patients were adults hospitalized with acute coronary syndromes or acute decompensated heart failure. Interventions included pharmacist-assisted medication reconciliation, inpatient pharmacist counseling, low-literacy adherence aids, and individualized telephone follow-up after discharge. Primary outcome was the number of clinically important medication errors per patient during the first 30 days post-hospital discharge. Secondary outcomes included preventable or ameliorable ADEs, as well as potential ADEs.


Mean age was about 60 years, 58% were male,75% were white, and 17% were black, annual household income was less than $50K in 55%, health literacy was considered adequate in over 80%, and over 90% had a primary care provider. Among 851 participants, 432 (50.8%) had one or more clinically important medication errors; 22.9% were judged to be serious and 1.8% life-threatening. ADEs occurred in 258 patients (30.3%) and potential ADEs in 253 patients (29.7%). The intervention did not significantly alter the per-patient number of clinically important medication errors (unadjusted incidence rate ratio, 0.92; 95% confidence interval [CI], 0.77-1.10) or ADEs (unadjusted incidence rate ratio, 1.09; 95% CI, 0.86-1.39). Patients in the intervention group tended to have fewer potential ADEs (unadjusted incidence rate ratio, 0.80; 95% CI, 0.61-1.04).


Clinically important medication errors were present among one half of patients after hospital discharge and were not significantly reduced by a health-literacy–sensitive, pharmacist delivered intervention.


The PILL-CVD (Pharmacist Intervention for Low Literacy in Cardiovascular Disease) study was well designed and implemented in a cohort in whom 50% had a history of coronary artery disease and coronary revascularization, suggesting they would have a familiarity with medication. While it would be nice to assume the failure to demonstrate a value was due to the excellent discharge planning process at the two academic medical centers involved, in fact there was a much higher incidence of ADEs in both the pharmacy intervention and usual care groups. This is despite a post-discharge phone follow-up. The incidence of ADE (30%) is double that previously reported, which may reflect the study design afforded a more thorough assessment via electronic medical records and more extensive review of outside medical records than was available in previous studies primarily conducted in Canadian hospitals in the early 2000s.

Clinical Topics: Acute Coronary Syndromes, Heart Failure and Cardiomyopathies, Atherosclerotic Disease (CAD/PAD), Acute Heart Failure

Keywords: Pharmacists, Medication Errors, Incidence, Coronary Artery Disease, Acute Coronary Syndrome, Follow-Up Studies, Drug-Related Side Effects and Adverse Reactions, Canada, Heart Failure, Cardiovascular Diseases, Primary Health Care

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