Utilization of ambulatory care services caused by adverse effects of medications in the United States.

Using the 1996 national ambulatory care surveys for the United States, this study examined the utilization of ambulatory care services because of the adverse effects of medications. Of the visits to ambulatory settings, 0.31% were because of adverse effects of medications, representing an estimated 2.73 million visits annually or 1.03 visits per 100 persons. Most (88%) of the visits were to office-based physicians, and the remainder were to hospitals. From both cost and quality perspectives, implementing strategies to prevent and/or effectively manage the adverse effects of medications could prove beneficial for payers and patients.