Patterns of Sleep-Related Medications Prescribed to Elderly Outpatients with Insomnia in Taiwan

Abstract

To explore prescription patterns and determinants of sleep-related medications prescribed to elderly outpatients with insomnia in Taiwan. This cross-sectional study was based on 2001 annual outpatient claims data released by the Bureau of National Health Insurance in Taiwan. The claims data of each physician consultation were extracted and merged in one claim file. International Classification of Diseases (9th Edition)-Clinical Modification codes, patient's demographics, physician's specialty, the medical institution code and the content of pharmaceutical prescription constituted a file. Patients were included if they were: (i) > or =65 years of age; and (ii) coded as having 'insomnia'. Elderly insomniacs made up 216,994 of the 1,000,193 outpatient claim files we surveyed. Patients had a mean age of 74.33 years, and the sex distribution was nearly equal. Based on the data above, 11.14% of the elderly had been diagnosed as having 'insomnia' for the year 2001. This population preferred primary-care clinics over hospital-ambulatory departments; patients most frequently sought medical help from internal medicine specialists. The most popular sleep medication was lorazepam, followed by zolpidem. The first-choice off-label drug used to treat insomnia was trazodone. Hypnotics, sedatives and anxiolytics were prescribed 12.6 times more frequently than off-label used drugs. When treating insomnia with an off-label drug, physicians usually prescribed a therapeutic dosage much lower than that recommended in the package insert. Choice of sleep medication and off-label drug were most often influenced by physician specialty. Off-label prescriptions were common but not prevalent. Choice of hypnotic or sedative-anxiolytic was related to how long the drug acted and how much it cost; choice of off-label drug was related to physicians' familiarity with specific drugs and patients' characteristics. Concomitant anxiety or depression was significantly associated with higher consumption of hypnotics. Benzodiazepines and newer non-benzodiazepine hypnotics are still the most frequently used drugs for treating insomnia in the elderly in Taiwan. Elderly patients with concomitant anxiety or depression consumed more hypnotics. Further studies conducted over several years are needed to identify trends in the pharmacological treatment of insomnia.