Prevalence and Socioeconomic Status of Patients with Genetic Myopathy in Korea: A Nationwide, Population-Based Study

Background: Genetic myopathy is a clinically and genetically heterogeneous group of genetic disorders characterized by progressive degeneration of skeletal muscles. Epidemiological studies of genetic myopathy have not yet been performed in Korea. Objectives: This study used data from the national health insurance claims database to determine the prevalence and socioeconomic status of patients with genetic myopathy in Korea. Methods: We analyzed the Health Insurance Review and Assessment database from 2007 to 2011. Patients with genetic myopathy were defined based on diagnostic and procedure codes. We then evaluated the prevalence, types of health insurances, and medical expenses of these patients. Results: During the 11-year study period, 2,988 patients with genetic myopathy were enrolled. Among them, 1,762 were men and 1,226 were women. The prevalence per 100,000 population in 2017 was 3.09 (3.94 for men and 2.24 for women). The prevalence of genetic myopathy among men <35 years old (8.33 per 100,000 population) was approximately twice that among women <35 years old (4.06 per 100,000 population). However, there was no significant difference in the prevalence of genetic myopathy among those ≥35 years old according to sex. The ratio of patients using medical aid among all genetic myopathy patients was approximately 4 times than that among the general population in Korea. The medical expenses per person for genetic myopathy increased from USD 2,027 in 2007 to USD 4,810 in 2017. Conclusions: Our study was the first nationwide epidemiologic study of the prevalence and socioeconomic status of patients with genetic myopathy in Korea. Our results confirmed a sex divergence in a younger population and those with low socioeconomic status among patients with genetic myopathy.