Nationwide epidemiologic study for pediatric osteomyelitis and septic arthritis in South Korea A cross-sectional study of national health insurance review and assessment service

Epidemiologic studies of pediatric bone and joint infection have been done mostly by developed Western countries, and such results could be expected to be biased. Therefore, an epidemiologic study to identify the distinct features of an Eastern country would be beneficial to improve their health outcomes and to reduce health care cost. A study was planned to investigate the epidemiology of pediatric osteomyelitis and septic arthritis in South Korea and to find out epidemiologic factors related with the occurrence of surgery. We conducted a cross-sectional study among hospitalized pediatric patients (<18 years old) with osteomyelitis and septic arthritis using nationwide cohort based on the Health Insurance Review and Assessment Service (HIRA) from 2008 to 2016. Percentage of hospitalization was additionally calculated according to several epidemiologic factors including age, month, site of infection, and region of residence. Logistic regression analysis was performed to find out the association between epidemiologic factors and occurrence of surgery Annual hospitalization rates (per 100,000) in our country were 7.8 to 9.1 for osteomyelitis, and 11.9 to 20.8 for septic arthritis. Frequent sites of osteomyelitis and septic arthritis were pelvis and lower extremity. The hospitalization rates of osteomyelitis and septic arthritis showed increasing trend with age. After multivariate logistic regression analysis, female gender, children, and adolescents rather than infants, rural area rather than urban area were associated with significantly increased odd ratios for surgery. The hospitalization rate of septic arthritis (11.9 to 20.8 per 100,000) in South Korea was higher than the Western countries (1.1 to 11 per 100,000), and the hospitalization rate of osteomyelitis (peak at 12 years) and septic arthritis (peak at 17 years) showed increasing trend with age, which was different from those of the developed Western countries showing higher incidence in children aged under 5 years. After multivariate logistic regression analysis, our study identified female gender, higher age group including children, and adolescents, and rural residence as epidemiologic risk factors associated with surgery.