Region-Based Analysis of Prevalence and Incidence of Parkinson's Disease: Analysis of the National Sample Cohort in South Korea

BACKGROUND AND PURPOSE: The rapid increases in the elderly population and urbanization in South Korea have influenced both demographics and the environment. This study investigated trends in the prevalence and incidence of Parkinson's disease (PD), and the associations of PD with the urban and rural environments in South Korea. METHODS: This study examined subjects aged 40 years or older in a cohort constructed using the National Sample Cohort data set in South Korea during 2002–2013. We estimated the age-standardized prevalence and incidence of PD based on the 2002 population, and estimated their trends. We analyzed regional differences in these rates by dividing South Korea into three regions based on geographic characteristics and two regions based on the degree of urbanization. RESULTS: The standardized prevalence rates of PD per 100,000 increased significantly from 75.8 in 2003 to 136.8 in 2012 (p 0.05). The standardized incidence of PD in younger subjects was lower in eastern Korea than in the other two regions, while in the older subjects it was lower in western Korea than in metropolitan Seoul over almost the entire analyzed period. The standardized incidence of PD did not differ significantly between metropolitan and nonmetropolitan areas. CONCLUSIONS: The standardized prevalence of PD increased steadily from 2003 to 2012 in South Korea, while its standardized incidence has remained constant. There were regional differences in the prevalence and incidence of PD based on the degree of urbanization and the area of agricultural land.

Femur Fractures in Parkinsonism: Analysis of a National Sample Cohort in South Korea

BACKGROUND AND PURPOSE: Falling with a femur fracture is a serious event that negatively affects the quality of life of elderly individuals as well as patients with parkinsonism. This study investigated the association between parkinsonism and femur fracture and compared the risk of femur fracture between subjects with and without parkinsonism. METHODS: This study examined a population-based matched cohort constructed using the National Sample Cohort data set, which comprises approximately one million subscribers to medical insurance and aid in South Korea. Subjects with parkinsonism during 2003–2013 were identified as the exposed group, and up to five individuals matched for age, sex, and index years were identified as the controls for each parkinsonism subject. The risk of femur fracture for parkinsonism was evaluated using Cox regression. RESULTS: The incidence of femur fracture according to age, sex, and body mass index varied significantly between subjects with parkinsonism and controls (p<0.001). The presence of parkinsonism was associated with a higher risk of femur fractures for males [hazard ratio (HR)=2.85, 95% confidence interval [CI]=1.87–4.34], subjects younger than 65 years (HR=2.89, 95% CI=1.64–5.11), and underweight subjects (HR=3.90, 95% CI=1.82–8.35). The adjusted HR for femur fracture with parkinsonism was highest within 2 years of the disease diagnosis (HR=3.10, 95% CI=2.12–4.53). CONCLUSIONS: Our study found that the presence of parkinsonism is more strongly related to femur fracture in males, and increases the influence of traditional risk factors on femur fracture. It is necessary to consider how factors associated with the amount of ambulatory activity–even in an early diagnosed state–can play an important role in femur fracture in subjects with parkinsonism.

Trends of Pars Plana Vitrectomy Rates in South Korea: A Nationwide Cohort Study

PURPOSE: To assess the trends in pars plana vitrectomy surgery rates and factors affecting rate change between 2002 and 2013 in South Korea. METHODS: Data from National Health Insurance Service-National Sample Cohort 2002–2013, which represents 1,025,340 samples with a sampling rate of 2.2% from the total eligible Korean population, was analyzed. RESULTS: A total of 3,816 vitrectomy procedures were performed (male, 2,010; female, 1,806) from 2002 to 2013. Annual rates of vitrectomy increased from 15.1 (in 2002) to 49.4 (in 2013) per 100,000 individuals, and this trend was prominent in those aged 60 years or older. As for the anesthetic method, vitrectomy under local anesthesia increased more prominently than vitrectomy under general anesthesia. The most common diagnoses associated with vitrectomy were diabetic retinopathy, retinal detachment, epiretinal membrane, and macular hole. CONCLUSIONS: The average annual rate of vitrectomy surgery was 31.5 per 100,000 between 2002 and 2013, and the rate has steadily increased.