Utilization of psychotropic drugs in Taiwan: an overview of outpatient sector in 2000.

Background: Development of pharmacological treatment in mental disorders has risen drastically over the past decade in Taiwan. We performed a survey of the National Health Insurance claims for outpatient psychiatric services to study the utilization of psychotropic drugs. The analysis followed the drug classification and standardized measurements proposed by the World Health Organization.

Methods: The sampling datasets from the National Health Insurance Research Database served as data sources. They represented 0.2% of the entire claims for outpatient medical services in 2000. The measurement units used for psychotropic drugs were either prescription volumes (drug items) or the number of defined daily doses (DDDs). To estimate the proportion of the population treated daily with psychotropic drugs, numbers of DDDs per 1000 inhabitants per day were also calculated. Beside overall description, the data of psychotropic substance prescriptions were analyzed by stratifying patient's age, physician's specialty, accreditation status of hospital, and chemical subgroup of psychotropic drugs.

Results: Prescription of psychotropic drug items (n = 63,539) was 3.24% of the total drug items (n = 1,958,820) claimed. The psychotropic drugs were prescribed to 9.2% of the total patients and in 9% of the total visits. Major consumers of psychotropic drugs were between 35-74 years of age and there were more women than men. The psychiatrist was the largest group of physicians who had prescribed psychotropic drugs and contributed 18.5% of all drug items and 38.3% of total DDDs of psychotropic drugs. The number of DDDs per 1000 inhabitants per day for all kinds of psychotropic drugs was estimated to be 32.94 in Taiwan, where anxiolytics accounted 14.30, hypnotics and sedatives 10.64, antipsychotics 3.41, antidepressants 3.06 and mood stabilizers 1.43. Ordered by total DDDs, the top 10 most frequently used chemical substances were flunitrazepam, alprazolam, fludiazepam, oxazolam, lorazepam, diazepam, zolpidem, estazolam, zopiclone, and haloperidol.

Conclusions: The usage level of psychotropic drugs in Taiwan was lower than in most industrialized countries, especially for antidepressants. The future goals are to focus on the longitudinal analysis of general trend for each psychotropic substance and to associate the pharmacoepidemiological data in parallel with the upcoming epidemiological study of mental disorders in Taiwan.