Disease Burden and Risk Factors of Hospitalized Community-Acquired Pneumonia in Korean Adults

Abstract

Background. Globally, pneumonia causes significant morbidity and mortality. Despite the recognized importance of community-acquired pneumonia (CAP) in adults, limited epidemiologic information is available in Korea. This study aimed to evaluate the disease burden of hospitalized CAP of adults aged >=19 years and their epidemiologic trends using national health-insurance and national mortality databases. Methods. Records of hospitalizations due to CAP were included for analysis, if the international Classification of Diseases, 10th revision (ICD-10) codes for pneumonia was listed for primary diagnosis. The incidence and risk factors of hospitalized CAP were evaluated. Results. During 2009-2013 years, 1,216,916 hospitalizations were recorded. The average annual rate of hospitalized CAP was 631 per 100,000 people, increasing with age (19-49 years, 165; 50-64 years, 527; 65-74 years, 1666; >=75 years, 4400 per 100,000 people). During 2009-2013, the overall rate of hospitalized CAP increased by 7.3% from 5.41 per 1000 people to 5.8 per 1000 people. The elderly aged >=75 years had the highest age-group-specific hospitalization rate for CAP over five-year study period. Total per-capita medical fees in all CAP patients were USD 1851 (KRW 1,934,410); they were USD 1263, USD 2353, USD 2841 in low, moderate, high risk patients, respectively. It tended to increase with aging. However, with respect to the underlying medical conditions (moderate- or high-risk group), the additional risk of hospitalized CAP was remarkable in adults aged under 65 years (odds ratio in moderate-risk and high-risk groups, 4.32 and 2.87 in 19-49 years; 1.80 and 3.66 in 50-64 years; 0.88 and 2.13 in 65-74 years; 0.99 and 1.97 in >=75 years). Conclusion. Overall, the disease burden of hospitalized CAP was increasing over recent years. Elderly people and adults with underlying medical conditions were at increased risk for hospitalized CAP. This study emphasize the importance of age-and risk based influenza and pneumococcal vaccination strategy.