Material and Method: The data on hospitalized pneumonia for the 2010 fiscal year, extracted from the three main health insurance coverage schemes in Thailand (the Social Security System (SSS), the Medical Welfare System (MWS), and the Civil Servant Medical Benefit System (CSMBS)) were analyzed.

Results: Adult hospitalized pneumonia admissions numbered 136,696, with mortality rate 9.63%. The mortality increased with increasing age, 15.49% for age >80 years. Influenza virus was the major etiology for 19 to 25 years old (49.30%) with low mortality (1-2%). S. pneumoniae and typical pathogens were found in every age group. The mortality rate for S. pneumoniae increased with age, viz. 0%, 1.96%, 5.56%, 7.02%, 6.98%, and 24.24% for 19 to 25, 26 to 40, 41 to 60, 61 to 70, 71 to 80, and 81+ years old. The mortality rate from C. pneumonia was about 10% and high among the younger age group. Gram-negative bacilli and Staphylococcus caused high mortality (about 20 to 35%), especially in the older age group. The major risk factors for increasing mortality were: elderly (OR 3.46, 95% CI 3.27-3.77), alcoholic liver disease (OR 3.26, 95% CI 2.85-3.72), cirrhosis (OR 3.45, 95% CI 2.93-4.08), heart disease (OR 2.47, 95% CI 2.38-2.56), ischemic heart disease (OR 2.21, 95% CI 2.07-2.36), renal failure (OR 5.26, 95% CI 5.07-5.49), and cerebrovascular disease (OR 3.62, 95% CI 3.43-3.82). The median length of hospital stay was four days (IQR, 3-7 days) and the median cost of treatment per admission was US$ 256.63 (IQR, US$ 147.81-531.21). Complications such as acute respiratory failure, acute respiratory distress syndrome (ARDS), septicemia, shock, and acute renal failure made hospital stays two to three days longer and costs three to seven times higher than no complications.

Conclusion: The mortality from pneumonia among the elderly was high, especially for those over 80 and with multiple medical co-morbidities.

Keywords: Adult pneumonia, Mortality rate, Pathogens, Risk factors