A spatial analysis of geographic variation and factors associated with hospitalization for bacterial pneumonia in Korea

Abstract

Background: The incidence of pneumonia in Korea started to increase in the 1990's after a period of decrease and stabilization, and the mortality and hospitalization rates for pneumonia in Korea are alarmingly high. This study was performed to examine geographic variation and factors associated with hospitalization for bacterial pneumonia in Korea.

Methods: Data were acquired from the inpatient claims of the 2015 period of the National Health Insurance Service. The age- and sex-standardized hospitalization rates for bacterial pneumonia were calculated for three age groups. Geographic variation was measured with the coefficient of variation, the ratio of the 90th to the 10th percentile of the distribution of rates, and the systematic component of variation. Considering the results of Moran's I statistic which suggested spatial autocorrelation, we estimated spatial regression models using spatial error models.

Results: The hospitalization rate for bacterial pneumonia was 79.1 per 10,000 population, and the rate was the highest in the age group 0-14 at 325.3, and it was 161.5 among the elderly. The geographic variation statistics showed high variation with the coefficient variation at 0.6. The deprivation score showed positive associations, and the number of primary care physicians had a negative association with the hospitalization rates across all age groups but the age group 0-14. The number of beds in hospitals with less than 300 beds had a positive association with the hospitalization rates for bacterial pneumonia, and the impact was the strongest in the age group 0-14.

Conclusions: The present study shows that pneumonia can be a major public health issue even in a developed country. Socioeconomic conditions can still be a concern for pneumonia in developed countries, and the role of primary care physicians in preventing hospitalization for bacterial pneumonia needs to be recognized. Most of all, the strong impact of hospital beds on the hospitalization rates for pneumonia, especially for the children, should be addressed. High disease burden of pneumonia in Korea can partly be attributable to oversupply of hospital beds. These factors should be taken into consideration in establishing policy measures for the rise in pneumonia.

Keywords: Bacterial pneumonia; Geographic variation; Hospital bed supply; Hospitalization; Korea; Pneumonia; Primary care; Regional deprivation; Spatial analysis; Spatial autocorrelation; Spatial regression.

Fig. 1

Map of preventable hospitalization rates due to bacterial pneumonia per 10,000 population in Korea in 2015. The figures were created by the author using the data provided by the National Health Insurance Service in Korea. The left upper map (for the group "All ages") was modified from the reference [30]