A Nationwide Cohort Study of Actinic Keratosis in Taiwan

Abstract

Summary Background Incidence of actinic keratosis (AKs) and nonmelanoma skin cancer appears to be increasing worldwide due to increasing levels of ultraviolet radiation, lifestyle changes, and an aging population. However, there is no population-based study focusing on AKs among Asian population. We aimed to investigate the incidence, the treatment pattern, the medical utilization and the risk of malignant neoplasm of the AKs patients in Taiwan. Methods We conducted a retrospective cohort study to investigate patients with AKs from 2003 to 2011 by using the National Health Insurance Research Database (NHIRD). The inclusion criteria were patients who had at least two outpatient visits or one hospital admission of AK identified by dermatologist from 2004 to 2011. There were 35,933 patients with AKs (elderly [aged ≥65 years]: n = 17,004; non-elderly [aged Results We found the incidence rate for AKs among elderly patients was higher than non-elderly. We further found that there were 923 patients were identified skin malignant neoplasm after diagnosis of AKs, and the incidence rate among elderly patients was higher than non-elderly (122.66 vs. 13.80 per 10,000 patient-year). Conclusions The AKs incidence rate was low in general population but particular high in elderly population in Taiwan. Our findings warrants further investigation into the relationship between actinic keratosis and the nonmelanoma skin cancer (NMSC) in Asians and may affect the approach toward primary prevention of NMSC in Asians with AKs.