Monitoring Severity of Respiratory Syncytial Virus (RSV) in Infants and Young Children Using the Pediatric RSV Electronic Severity and Outcome Rating System (PRESORS): Results of Initial Quantitative Validation.

Purpose: PRESORS ClinRO completed by clinicians and ObsRO completed by caregivers were developed to characterize the clinical course of respiratory syncytial virus (RSV) infection. This study describes preliminary analysis of PRESORS' measurement properties using clinical trial data.

Patients and methods: PRESORS ClinRO and ObsRO data were collected in a 28-day randomized, double-blind, Phase 1b trial of JNJ-53718678 or placebo in infants and children ≤24 months of age treated for RSV infection in hospitals. PRESORS data were scored and key psychometric properties of scores were evaluated, including ability to discriminate between known groups and to detect change over time. Time to resolution of RSV signs was explored using two responder definitions.

Results: Daily completion rates for PRESORS ClinRO and ObsRO were high for the 44 children in the study (median: 100% and 93%, respectively). Large floor effects were observed at baseline for signs of severe RSV infection that were either absent (cyanosis, fever, apnea) or rarely reported (reduced urination/dehydration, vomiting). Implausible ObsRO ratings suggested some caregivers could not accurately measure heart rate. Known-group validity was confirmed: children in poor health based on baseline ClinRO had mean baseline composite scores that were significantly worse for both ObsRO (p=0.001) and ClinRO (p<0.001) compared to those with better overall health. ObsRO (p=0.009) and ClinRO (p<0.001) composite scores were responsive to change in overall health status from baseline to Day 3. Mean scores for RSV sign dimensions decreased rapidly from baseline to Day 7 except for coughing and sleep ratings by caregivers. Time to recovery varied greatly depending on definitions used.

Conclusion: PRESORS ClinRO and ObsRO can inform endpoints and enable monitoring the clinical course of RSV in pediatric trials. Improved alignment between ClinRO and ObsRO and revisions ensuring caregivers can assess all signs will be addressed in revised PRESORS.