Epidemiology of ALS in Korea using nationwide big data

Abstract

Objective: This study aimed to determine the incidence, prevalence and survival time of Korean patients with amyotrophic lateral sclerosis (ALS) using National Health Insurance Service (NHIS) data.

Methods: Using NHIS data, the Korean nationwide health dataset, we identified patients with motor neuron diseases who were first diagnosed with a KCD-6 code (G12.20-G12.28; modified from ICD-10 codes) between 2011 and 2015. ALS (G12.21 code) epidemiological characteristics, including annual incidence, prevalence, mortality rates and survival time, were analysed and compared with sociodemographic variables.

Results: New patients with ALS (n=3049) were enrolled over 5 years. The mean annual incidence was 1.20/100 000, and the sex ratio was 1.60 (male:female). The mean age at the time of diagnosis was 61.4 years. The prevalence rate was 3.43/100 000 in 2015. In this period, riluzole was prescribed to 53.6% of patients with ALS. Furthermore, 20.3% of patients with ALS underwent tracheostomy. When analysed for age and socioeconomic status, ALS prevalence rate was 10.71 in the aged group (≥60) in 2015 and was lowest in the middle-income group compared with that in the high-income and low-income groups. The estimated mean survival time in this population was 50.0 months, and the 3-year and 5-year mortality rates were 52.1% and 63.7%, respectively.

Conclusions: This study is the first nationwide survey for epidemiological characteristics of ALS in Korea using national data. The use of these data substantially advances the understanding of Korean and Asian ALS epidemiology and its relationship with socioeconomic status, age and sex.

Keywords: amyotrophic lateral sclerosis; epidemiology; incidence; prevalence.

Figure 1

Comparison of the survival curves from the time of diagnosis to the time of death in patients with amyotrophic lateral sclerosis shows significant differences in symptom onset age (2011–2015). This shows that the younger symptom onset age group had relatively longer survival time compared with that of the older group (log-rank test, p<0.0001, both).