Prevalence of psychiatric disorders among National Health Insurance enrollees in Taiwan

Objective: About 96 percent of all residents of Taiwan were enrolled in the National Health Insurance (NHI) program in 2000. This study used claims data from the NHI database to determine the prevalence of and the demographic characteristics that are associated with psychiatric disorders. Methods: A total of 200,432 persons, about 1 percent of Taiwan's population, were randomly selected from the NHI database. Persons under the age of 18 years and persons who were not eligible for NHI in 2000 were excluded, leaving 137,914 persons available for this study. Data for enrollees who had at least one service claim during 2000 for ambulatory or inpatient care for a principal diagnosis of a psychiatric disorder were classified into one of the psychiatric disorder categories according to ICD-9-CM diagnostic criteria. Data from the 2000 NHI study were compared with data from a 1985 community survey, the Taiwan Psychiatric Epidemiological Project, to determine how the prevalence of psychiatric disorders changed over the 15-year period. Results: The one-year prevalence of any major psychiatric disorder, any minor psychiatric disorder, and any psychiatric disorder were 1.37 percent, 4.26 percent, and 5.30 percent, respectively. The differences in prevalence between the sexes were significant for five major and nine minor psychiatric disorders. The prevalence for eight psychiatric disorders were lower in the 2000 NHI study than in the 1985 community survey. However, the prevalence of schizophrenic disorder was found to be higher in the 2000 study and the prevalence of bipolar disorder was found to be the same in both studies. Conclusions: Because the prevalence of psychiatric disorders were generally lower in this study and in the 1985 community survey than those in other countries, it was concluded that both major and minor psychiatric disorders were undertreated in Taiwan. It is necessary for the public health department and the general population to emphasize mental illness education, prevention, and treatment in Taiwan.