Relationship between Potentially Inappropriate Anticholinergic Drugs (PIADs) and Adverse Outcomes among Elderly Patients in Taiwan
KUANG-HUA HUANG1, YI-FANG CHAN1,2, HUNG-CHE SHIH3,4 AND CHIEN-YING LEE3,4*
1. Department of Health Service Administration, College of Public Health, China Medical University, Taichung, Taiwan, R.O.C.
2. Department of Medical Affairs, KuangTienGeneralHospital, Taichung, Taiwan, R.O.C.
3. Institute of Medicine, ChungShanMedicalUniversity, Taichung, Taiwan, R.O.C.
4. Department of Pharmacy, ChungShanMedicalUniversityHospital, Taichung, Taiwan, R.O.C.
(Received: November 8, 2011; Accepted: August 8, 2012)
ABSTRACT
The Beers’ criteria indicate that some anticholinergic drugs are inappropriate for treating elderly patients, but those most frequently used anticholinergic drugs in previous studies. This study was aimed to explore the association between the potentially inappropriate anticholinergic drugs (PIADs) and adverse outcomes among elderly people in Taiwan. A retrospective cohort study was conducted by analyzing the Longitudinal Health Insurance Database (LHID2005) of the National Health Insurance Research Database (NHIRD) from 2007 to 2008 to investigate all prescriptions for elderly people above the age of 65. The anticholinergic risk scale (ARS) constituted the criteria for PIADs. Adverse outcomes included emergency visits, hospitalization, and adverse drug reactions (ADRs) such as constipation, delirium, cardiac arrhythmia, and cognitive impairment. The prevalence of PIADs was 18.67% in outpatient prescriptions. Approximately 75.65% of outpatients have received at least one PIAD. After adjusting for age, gender, the number of drug items, and CCI, patients, who have received PIADs, had higher risks of emergency visits, hospitalization, constipation, delirium, and cardiac dysrhythmia (odds ratio [OR] = 1.85, 1.07, 1.87, 1.51 and 1.16) than those who have never received PIADs. This study suggests that physicians should be cautious when prescribing anticholinergic drugs for elderly patients to reduce the risk of adverse outcomes and improve the safety of medicating elderly people.
Key words: elderly patients, potentially inappropriate anticholinergic drugs (PIADs), anticholinergic risk scale (ARS), adverse outcomes, adverse drug reactions (ADRs)