Incidence and prevalence rates of diabetes mellitus in Taiwan: Analysis of the 2000–2009 Nationwide Health Insurance database

Formerly, Taiwan's diabetic population has been estimated by surveys conducted at irregular intervals and using different sampling methods. To obtain nationwide data on the incidence and prevalence of diabetes mellitus (DM) in Taiwan, we performed an analysis of the 2000–2009 claim data from the National Health Insurance (NHI) database. Methods: One-third of the claims in the NHI database from 2000 to 2009 were randomly sampled. DM was defined by three or more outpatient visits with diagnostic codes (ICD-9-CM: 250 or A code: A181) within 1 year or by one inpatient discharge diagnosis of DM. Confirmation of type 1 diabetes mellitus was based on the issue of a catastrophic illness certificate with the same diagnostic codes. Age and/or gender distribution for DM were determined. Results: In accordance with the global trend for DM, with a near constant standardized incidence rate, there was a more than 70% increase in the total diabetic population, or a 35% increase in the standardized prevalence rate, in Taiwan from 2000 to 2009. The incidence of diabetes was higher in men, especially in the 20–59-year-old age group, and the total number of men with diabetes exceeded the number of women with diabetes in 2005. However, the prevalence and incidence rates in women over the age of 60 years were higher than those in men. Type 1 DM was present in less than 1% of the diabetic population in Taiwan. Conclusion: The incidence of diabetes, including type 1, remained stable over this 10-year period in Taiwan. However, the incidence rate in men aged 20–59 years was higher than that in age-matched women. With our nationwide database, subgroup analysis of DM incidence can be performed to refine our health policies for the prevention, screening, and treatment of diabetes mellitus.