Streptococcus pneumoniae is the main cause of community-acquired pneumonia (CAP) in adults.
Objectives: To compare accuracy and discriminatory power of three validated rules for predicting clinically relevant adverse outcomes in patients hospitalized with community-acquired pneumococcal pneumonia.
Measurements: We prospectively compared the pneumonia severity index (PSI), British Thoracic Society score (CURB-65) and severe CAP score (SCAP) in a cohort of 151 consecutive immunocompetent adult patients hospitalized with pneumococcal pneumonia. Major adverse outcomes were admission to ICU, need for mechanical ventilation, in-hospital complications and 30-day mortality. Mean hospital length of stay (LOS) was also evaluated. The predictive indexes were compared based on sensitivity, specificity, and area under the curve of the receiver operating characteristic.
Results: The mean age of 151 immunocompetent adult patients hospitalized with pneumococcal pneumonia was 64 years (range, 16 to 92); 58% were male, 75% had comorbidities, 26% were admitted to the intensive care unit and 9% needed mechanical ventilation. The rate of all adverse outcomes and hospital LOS increased directly with increasing PSI, CURB-65 and SCAP scores. The three severity scores allowed us to predict the risk of in-hospital complications and 30-day mortality. The PSI score was more sensitive and the SCAP was more specific to predict in-hospital complications and the risk of death. However, the SCAP was more sensitive and specific in predicting the use of mechanical ventilation.
Conclusion: The severity scores validated in the literature allow us to predict the risk of complications and death in adult patients hospitalized with pneumococcal pneumonia. Nevertheless, the clinical indexes differ in their sensitivity, specificity and discriminatory power to predict different adverse events.