Key Point

Pneumonia severity scores vary in their ability to predict outcomes of patients with community-acquired pneumonia.

VICTORIA, AUSTRALIA—Victoria, Australia—A recent study by Buising and colleagues was the first to compare five well-known pneumonia severity scores: the Pneumonia Severity Index (PSI), CURB, CURB-65, the modified British Thoracic Society (BTS) score, and the revised American Thoracic Society (ATS) score.¹

"The results show that different severity scores for community-acquired pneumonia have different strengths and weaknesses depending on which patients the clinician really wants to identify," the authors reported. The CURB-65 score, for example, accurately predicted mortality but not the need for ICU admission or the combination of those outcomes. The revised ATS score was a sensitive predictor of ICU admission but not death. The PSI performed reasonably well in all areas, and the CURB score was similar in accuracy to the PSI, said the authors.

"The existing severity scores have been derived using predictors of mortality, so constructs to represent ‘severe pneumonia’ rather than just ‘pneumonia leading to death’ needed to be looked at," principal author Kirsty L. Buising, MD, told Pulmonary Reviews. "That is why we tested severity scores for their value in predicting more clinically meaningful outcomes," explained Dr. Buising, a Clinical Research Fellow in the Victorian Infectious Diseases Service at Melbourne Hospital in Victoria, Australia.

The five scores were evaluated in a prospective cohort of 392 patients hospitalized with a diagnosis of community-acquired pneumonia.

Of the patients, 6.6% were admitted to the ICU and 9.4% died. Excluding those who were not treated with antibiotics or who had suspected aspiration pneumonia, 36% did not receive a recommended antibiotic regimen.

For predicting mortality, the combination of PSI classes IV and V was most sensitive (97.3%) but the least specific (47.9%). The revised ATS score was most specific (84.6%) but the least sensitive (40.5%). At 96%, the modified BTS score was the most sensitive predictor of ICU admission but it was also the least specific for that outcome (48.7%). The revised ATS score was most specific (87.3%) and the second-most sensitive (92%) for predicting ICU admission.

—Timothy Begany

Reference
1. Buising KL, Thursky KA, Black JF, et al. A prospective comparison of severity scores for identifying patients with severe community acquired pneumonia: reconsidering what is meant by severe pneumonia. Thorax. 2006;61:419-424.

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