Validation of a prediction rule for prognosis of severe community-acquired pneumonia

In a previous study, we developed a prognostic prediction rule, based on nine prognostic variables, capable to estimate and to adjust the mortality rate of patients admitted in intensive care unit for severe community-acquired pneumonia. A prospective multicenter study was undertaken to evaluate the performance of this rule. Five hundred eleven patients, over a 7-year period, were studied. The ICU mortality rate was 29.0%. In the 3 initial risk classes, we observed significantly increasing mortality rates (8.2% in class I, 22.8% in class II and 65.0% in class III) (p<0.001). Within each initial risk class, the adjustment risk score identified subclasses exhibiting significantly different mortality rates: 3.9% and 33.3% in class I; 3.1%, 12.9% and 63.3% in class II; and 55.8% and 82.5% in class III. Compared with mortality rates predicted by our previous study, only a few significant differences were observed. Our results demonstrate the performance and reproductibility of this prognostic prediction rule.