BACKGROUND: Taiwan introduced PharmaCloud, a system designed to streamline access to comprehensive medication records from various healthcare settings. Despite its potential, the impact of physician-led medication reconciliation (MR) utilizing PharmaCloud on outpatient outcomes remains unclear. This study aims to address this gap by evaluating the effectiveness of PharmaCloud-enabled MR in improving patient outcomes. METHODS: We collected data from outpatients with major polypharmacy (≥ 10 medications) between May 19, 2019, and April 18, 2020, comparing those who received MR with those who did not. Outcomes including total medical expenditures, ED visits, hospitalizations, mortality rate, and number of medications were compared between the two cohorts over a 12-month follow-up period. RESULTS: The study enrolled 209 patients with MR and 9,053 patients without MR. Patients who received MR were older, had lower body mass index, took more medications, and had a higher prevalence of hypertension, cerebrovascular disease, chronic kidney disease, and mental disorder. After 12 months of follow-up, patients who received MR had a higher proportion of reduced medications (adjusted odds ratio: 1.4
95% confidence interval: 1.0 - 2.0), but also had more ED visits in the first 12 months compared to those who did not receive MR. The study did not find any significant differences in total medical expenditures, hospitalizations, and mortality rates between the two cohorts. CONCLUSIONS: The model reduced medication use. Further research, including prospective designs, pharmacist involvement, and evaluations of reduced complications from fewer medications, is needed to better clarify patient outcomes.