2359. Validation of a Novel Scoring Criteria for Assessing the Severity of Viral Respiratory Infections in Children

BACKGROUND: Novel investigative tools (e.g., whole-genome sequencing) help characterize host and viral genetic contributions to disease severity in pediatric viral respiratory infection. However, a validated scoring system for quantifying illness severity is needed to properly contextualize results. Existing scoring systems are outdated, unvalidated and underpowered. We thus developed a scoring system to address these concerns. METHODS: Children hospitalized with viral respiratory infections were prospectively enrolled over 2 years, with 51 clinical variables abstracted from the medical record. 7 variables felt to be most predictive of disease severity and significantly correlated with each other (Spearman correlation coefficient P < 0.001) were included in the scoring system (duration of hospital and ICU stay, oxygen and high flow nasal cannula (HFNC) use and intubation; maximum nasal cannula and HFNC support), and combined into a disease severity index by converting each into an ordinal score and summing over the variables, with each variable sub-divided into 7 levels of exposure (based on equal interval length cutpoints). For a validation comparison, sampling algorithms utilizing a linear model selected a subset of 96 patients whose disease severity would be randomly assessed by 8 pediatricians in blocks of 12, using D-optimality and space filling criteria to protect against non-linearity (severity scored 1 to 10; 80% power for detection of correlation >0.28, two-sided α = 0.05). Mixed model regression analyses compared clinician-scored disease severity with the scoring system. Akaike Information criteria (AIC) and coefficients of determination (R(2)) ranked severity indices. RESULTS: 445 subjects (56.2% male, median age 1.2 years) were enrolled. Clinician scores of disease severity averaged 6.2 (SD = 2.2, range 1–10). A scoring system using 7 variables with 7 levels of exposure per variable produced the lowest AIC (0.00, R(2) = 0.70 for predicting clinician-scored disease severity after adjustment for rater effects) (Figure 1). CONCLUSION: A 7-variable scoring system quantifying disease severity in pediatric viral respiratory infections correlates well with clinician assessment, and may advance the study of such infections. Figure 1: Fitted model: Association of Clinician Score and Severity Scoring System. DISCLOSURES: All authors: No reported disclosures.