External Validation of Risk Scores for Pediatric Pneumonia

Abstract

Background: Neither the Pneumonia Risk Score ( PRS ) nor the VALS-DANCE diagnostic tool has been externally validated using a reference standard specific for bacterial pneumonia. We used a previously published cohort of children with suspected bacterial pneumonia to externally validate these scores. Methods: Children attending Canadian pediatric emergency departments with suspected pneumonia had extensive standardized data collected that were provided to an expert panel to reach a consensus diagnosis. This diagnosis was used to externally validate both clinical scores. Proportions, point estimates and 95% confidence intervals (CIs) were calculated, as appropriate, for the classifications and cutoffs recommended for PRS and VALS-Dance. Results: In a cohort of 236 children, the PRS classified 69 as low risk, 155 as moderate risk and 12 as high risk for “radiographic” pneumonia. Of these, 11/69 (15.9%), 44/155 (28.4%) and 5/12 (41.7%), respectively, had bacterial pneumonia, yielding a receiver operating characteristic curve of 0.64 (95% CI 0.56–0.71). The PRS low-risk grouping yielded negative likelihood ratio (−LR) 0.56 (95% CI 0.24–0.88) and the high-risk grouping a positive LR (+LR) 2.10 (95% CI −0.23 to 4.42) for bacterial pneumonia. In a cohort of 94 children, the VALS-DANCE Step1 cutoff yielded +LR 2.97 (95% CI 1.52–4.08) and −LR 0.19 (95% CI 0.05–0.33) for distinguishing bacterial from viral pneumonia. In a cohort of 53 children, the VALS-DANCE Step2 cutoff yielded +LR 13.1 (95% CI 0.83–208.8) and −LR 0.65 (95% CI 0.51–0.84) for distinguishing typical from atypical bacterial pneumonia. Conclusions: The PRS may have limited utility in the emergency department in guiding clinicians as to whether children with suspected pneumonia need antibiotics. For children hospitalized with community-acquired pneumonia, the VALS-DANCE Step1 diagnostic tool may have some utility for ruling out, but little for confirming bacterial pneumonia. For those with bacterial pneumonia, VALS-DANCE Step2 has uncertain utility for confirming typical and little utility for diagnosing atypical pneumonia.