Evaluation and Refinement of a Prognostic Indicator of Pediatric Severity in Young Children with Pneumonia Enrolled in the CDC Etiology of Pneumonia in the Community (EPIC) Study

Background:   Effective management of pneumonia involves assessing the severity of illness and likelihood of developing complications. While clinical prediction scores for community-acquired pneumonia (CAP) have been developed and validated for adults, no such pediatric prediction score has been available.  To address this deficiency, the Respiratory Index of Severity in Children (RISC) was developed based on mortality in young children with lower respiratory infection in South Africa. RISC assigns a point value to 5 predictors (oxygen saturation, chest indrawing, weight for age, feeding refusal, and wheezing) based on the magnitude of their association with mortality; the overall score was shown to predict the risk of mortality.  This study sought to evaluate and refine the RISC tool for children in a high-resource setting.

Methods:   The CDC EPIC study enrolled children with CAP at 3 children’s hospitals in Memphis, Nashville, and Salt Lake City; we included children age <5 years enrolled from 1/1/2010–6/30/2011.  Mortality in children with CAP in the US is rare, thus we used a combined endpoint of mechanical ventilation or death.  We initially evaluated the ability of the 5 variables included in the RISC score to predict these outcomes.

Results:   Among 1027 children aged <5 years, 74 (7%) were mechanically ventilated and 3 (0.3%) died.  The association between the RISC predictors and these outcomes are displayed below.

Table.  Association of selected predictors with severe outcomes

	Points in RISC score	% of total (n=1027)	% of outcomes (n=76)	OR	95%CI
Oxygen saturation
<90%*	3	27	29	1.1	0.7–1.9
<85%		11	20	2.3	1.3–4.2
<80%		5	13	3.9	1.8–8.2
Chest indrawing	2	60	73	1.9	1.1–3.2
Weight for age
Low (–3 < z ≤ –2)	1	5	8	2.0	0.8–4.9
Very low (z ≤ –3)	2	4	12	4.0	1.8–8.8
Refusing feedings	1	75	68	0.7	0.4–1.2
Wheezing	–2	41	41	1.0	0.6–1.6

^* indicates oxygen saturation threshold included in RISC score

Conclusion:   Low oxygen saturation at admission, chest indrawing, and low weight for age were predictors of severe outcomes in this study.  Oxygen saturation was associated with outcomes at a lower threshold than in the RISC study, suggesting that supplemental oxygen along with other supportive measures in a high resource setting may mitigate severe outcomes from CAP.  Evaluation of additional factors that may improve the RISC score in this setting is in progress.