The overarching objective of this research study is to pursue a large randomized controlled trial (RCT) focused on older patients recently discharged from the hospital who have been prescribed medications within one of three high-priority, high-risk drug classes in order to reduce the risk of clinically important medication errors. The National Action Plan for Adverse Drug Event (ADE) Prevention identified three high-priority drug classes as key targets for reducing the risk of drug-related injuries: anticoagulants; diabetes agents (insulin and oral agents); and opioids. These medication classes were chosen because they account for the greatest number of measurable drug-related harms to patients, and a substantial proportion of ADEs associated with these medications is considered preventable. The clinical trial will determine the value of a multifaceted medication error and ADE reduction intervention with a special focus on in-home assessment.