Yonsei Med J.  2016 Mar;57(2):419-425. 10.3349/ymj.2016.57.2.419.

The Epidemiology of Myasthenia Gravis in Korea

• Lee HS
• Lee HS
• Shin HY
• Choi YC
• Kim SM

• KMID: 2374048
• DOI: http://doi.org/10.3349/ymj.2016.57.2.419

Abstract

PURPOSE
An epidemiological study of myasthenia gravis (MG) has not been performed in Korea. The purpose of this study was to estimate the prevalence and incidence of MG in Korea.
MATERIALS AND METHODS
Health Insurance Review and Assessment (HIRA) data from 2010 to 2014 were searched for MG codes as defined by the International Classification of Diseases, 10th revision. After identifying MG cases, we estimated the prevalence and annual incidence of MG based on the HIRA database and Korean population data.
RESULTS
During the study period, 10138 MG cases were identified. The prevalence of MG was 10.42 cases per 100000 people in 2010 and this increased every year to 12.99 cases per 100000 people in 2014. The average incidence of MG between 2011 and 2014 was 0.69 cases per 100000 person-years. The prevalence and incidence were higher in the older (> or =50 years) age group than in the younger (<50 years) age group [prevalence: 9.26 vs. 19.24 per 100000, relative risk 2.077, 95% confidence interval (CI) 1.976-2.183, p<0.001; incidence: 0.47 vs. 1.18 per 100000, relative risk 2.490, 95% CI 2.006-3.091, p<0.001].
CONCLUSION
This study was the first nationwide population-based epidemiological study of MG in Korea. The prevalence and incidence of MG were consistent with those of previous studies. We found an increase in the prevalence of MG and a predominance of elderly MG patients.

Keyword

Myasthenia gravis; prevalence; incidence; epidemiology; nationwide population-based; Korea

MeSH Terms

Adolescent
Adult
Age Distribution
Aged
Aged, 80 and over
Child
Child, Preschool
Databases, Factual
Female
Humans
Incidence
Male
Middle Aged
Myasthenia Gravis/*epidemiology
*Population Surveillance
Prevalence
Republic of Korea/epidemiology
Young Adult

Figure

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  Fig. 1 The population pyramid in 2010, South Korea.

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  Fig. 2 The number of MG cases in 2012 (A: by age group, B: by sex and age group). MG, myasthenia gravis.

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  Fig. 3 The prevalence in 2012 (A: by age group, B: by sex and age group). MG, myasthenia gravis.

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  Fig. 4 The new MG cases during the study period (A: by age group, B: by sex and age group). MG, myasthenia gravis.

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  Fig. 5 Average incidence from 2011 to 2014 (A: by age group, B: by sex and age group). MG, myasthenia gravis.

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