Potentially inappropriate medication for emergency department visits by elderly patients in Taiwan.

PURPOSE: The potential for adverse drug events caused by potentially inappropriate medication (PIM) use in elderly patients at emergency department (ED) visits is a growing concern. The objects of this study were to determine the prevalence, characteristics and risk factors of PIM use among elderly ED visits in Taiwan.

METHODS: The nationwide computerized claims database of elderly ED visits under the National Health Insurance (NHI) in Taiwan during 2001-2004 was accessed. PIM, independent of diseases diagnoses or conditions and should be generally be avoided in elderly people, was evaluated using the updated 2003 Beers criteria.

RESULTS: Between 2001 and 2004, 14.7% of total 1 429 463 elderly ED visits with prescriptions had PIM, and 19.3% of elderly people who visited ED received at least one PIM annually. Odds ratio for PIM prescriptions to ED elderly was higher for visits at which more drugs were prescribed, visits at local community hospital, female and older physicians, patients aged 65-69 years and female patients. Common PIM categories were short acting nifedipine, muscle relaxants and anti-spasmodics, antihistamines and ketorolac. When health care resource utilization was compared in 2004, subjects receiving PIM at ED visit had significantly more mean ambulatory care visits, ED visits and hospital admissions than subjects who did not receive PIM.

CONCLUSIONS: About one fifth of elderly people who visited ED received PIM annually in Taiwan. The public and physicians should be educated, and a computerized drug surveillance system might be needed to avoid PIM prescriptions to the ED elderly patients.