Incidence, prevalence and mortality of amyotrophic lateral sclerosis in Taiwan

Objectives: Amyotrophic lateral sclerosis (ALS) is a senous disease. Therefore, monitoring basic epidemiologicalindicators for clarifying the epidemic trend is crucial. Yearly epidemiological statistical data were determined to assess the incidence, prevalence, and mortalityof ALS in Taiwan. Methods: In this population-basedretrospective cohort study, patients who were newly diagnosed with ALS from January 1, 1999, to December 31, 2017, were enrolled from the Registry for Catastrophic Illness Patient Database. Medical claims from the National Health Insurance Research Database and national mortality database were linked for further analysis. Results: The age-standardized incidence rate of ALS in 2008-2015 was approximately 0.33 to 0.44 per 100,000 people. The age-standardized prevalence rate increased from 1.54 in 2008 to 2.31 in 2015 (per 100,000 people). High mortality rate (annual crude mortality rate = 14.7%a-19.7%) was observed within 5 years after the date of the first diagnosis in 1999-2016. The analysis of confirmed death cases only indicated that the average survival time improved significantly in patients who underwent tracheostomy, noninvasive ventilator use, or gastrostomy (4.92 years versus 2.66 years, 3.56 years versus 2.45 years and 3.75 years versus 3.02 years, respectively). Conclusions: Following ALS epidemiological data during 1999-2007 in Taiwan, this study revealed that the annual incidence rate of ALS in Taiwan was stable from 2008 to 2015. However, the trend of the annual prevalence rate increased gradually. The mortality rate within 5 years after the initial diagnosis was high, and treatment with tracheostomy, noninvasive ventilator se, and gastrostomy can prolong survival time.