Title:
Medication reconciliation accuracy and patient understanding of intended medication changes on hospital discharge.

Abstract:
Adverse drug events after hospital discharge are common and often serious. These events may result from provider errors or patient misunderstanding.
To determine the prevalence of medication reconciliation errors and patient misunderstanding of discharge medications.
Prospective cohort study
Patients over 64 years of age admitted with heart failure, acute coronary syndrome or pneumonia and discharged to home.
We assessed medication reconciliation accuracy by comparing admission to discharge medication lists and reviewing charts to resolve discrepancies. Medication reconciliation changes that did not appear intentional were classified as suspected provider errors. We assessed patient understanding of intended medication changes through post-discharge interviews. Understanding was scored as full, partial or absent. We tested the association of relevance of the medication to the primary diagnosis with medication accuracy and with patient understanding, accounting for patient demographics, medical team and primary diagnosis.
A total of 377 patients were enrolled in the study. A total of 565/2534 (22.3 %) of admission medications were redosed or stopped at discharge. Of these, 137 (24.2 %) were classified as suspected provider errors. Excluding suspected errors, patients had no understanding of 142/205 (69.3 %) of redosed medications, 182/223 (81.6 %) of stopped medications, and 493 (62.0 %) of new medications. Altogether, 307 patients (81.4 %) either experienced a provider error, or had no understanding of at least one intended medication change. Providers were significantly more likely to make an error on a medication unrelated to the primary diagnosis than on a medication related to the primary diagnosis (odds ratio (OR) 4.56, 95 % confidence interval (CI) 2.65, 7.85, p<0.001). Patients were also significantly more likely to misunderstand medication changes unrelated to the primary diagnosis (OR 2.45, 95 % CI 1.68, 3.55), p<0.001).
Medication reconciliation and patient understanding are inadequate in older patients post-discharge. Errors and misunderstandings are particularly common in medications unrelated to the primary diagnosis. Efforts to improve medication reconciliation and patient understanding should not be disease-specific, but should be focused on the whole patient.