The Geriatric Emergency Department Pharmacologic Harm Prevention Project

The goal of this project is to determine whether pharmacogenomic testing (using participants' DNA) can help optimize medication prescribing and reduce side effects in older adults taking five or more medications. The main questions it aims to answer are: * Can DNA-based prescribing reduce medication-related side effects, especially falls and fall-related injuries? * Does providing pharmacogenomic results to primary care physicians improve medication safety compared with usual care? Researchers will compare two groups: 1. DNA Care Pathway: Physicians receive patients' DNA results to guide prescribing. 2. Emergency Department Care Pathway: Physicians provide usual care; DNA results are shared only after study completion. Participants will: * Provide a cheek swab sample for DNA analysis (1 minute). * Receive monthly follow-up phone calls for 6 months to track falls, injuries, medication changes, and side effects. * Complete a fall and medication calendar. * Allow researchers to review primary care physician medical records for study outcomes. Approximately 1,000 participants will take part, with follow-up lasting about 6-7 months.