The aim of this study was to determine the prevalence, treatment modalities and comorbidity of psoriasis in Taiwan. A nationally representative cohort of 1,000,000 individuals from the National Health Insurance database was followed up for the years 2000 to 2006. Their claims data was used for an epidemiological study. The mean one-year prevalence of psoriasis was 0.23% for men and 0.16% for women, respectively. The prevalence of psoriasis increased more rapidly in male patients aged 30 years and over and reached its peak in patients aged 70 years and over, regardless of sex. Overall, 98.4% of patients received treatment with topical corticosteroids, while 13.1% used Chinese herbal medicines and 13.6% received systemic treatment. Patients with psoriasis had a higher comorbidity of diabetes, hyperlipidaemia, and hypertension. In conclusion, in contrast to Caucasians, the prevalence of psoriasis in Taiwanese people is high er in men than in women and the prevalence increases significantly in patients over 70 years of age.

To analyse the epidemiological characteristics and related costs of herpes zoster in Taiwan, a nationally representative cohort of 1,000,000 individuals from the National Health Insurance register was followed up from 2000 to 2006 and their claims data analysed. Overall, 34,280 patients were diagnosed with zoster (incidence 4.89/1000 person-years) and 2944 patients (8.6%) developed post-herpetic neuralgia 3 months after the start of the zoster rash (incidence 0.42/1000 person-years). People with older age, diabetes, and immunocompromising conditions were at higher risk of developing zoster and post-herpetic neuralgia. The overall hospitalization rate for zoster was 16.1 cases per 100,000 person-years. The cost for each home care case and per hospitalized case were approximately 53.30 euro and 1224.70 euro, respectively. Further research into the cost-effectiveness of zoster vaccine is needed.

This is the first large-scale study to report the associated malignancies and the cancer risk of IIM in Taiwan.