Visits to Hospital Outpatient Departments in the United States Due to Adverse Effects of Medications

Using 1995–1996 National Hospital Ambulatory Medical Care Surveys, this study examined the prevalence, nature, and demographics of visits to hospital outpatient departments (OPDs) for adverse effects of medications, and the resource utilization associated with these visits. Weighted analyses of visits resulting in principal diagnoses of adverse effects of medications revealed that 0.19% of OPD visits were due to such incidents. These estimates projected annually represent 125,508 visits or 4.77 visits per 10,000 persons. The highest visit rates were seen in females, patients over 74 years old, and patients living in the Midwest. The agents most often responsible for these visits were hormones, antibiotics, and analgesics. The most frequently cited reasons for the visits were adverse effects of medications and skin rashes. Many medication-related OPD visits require diagnostic services and pharmacotherapy, thus a reduction in these problems would decrease the burden on health care systems.