Content validation of a caregiver diary to monitor severity and recovery of pediatric patients with respiratory syncytial virus infection.

Background: Respiratory Syncytial Virus (RSV) is a leading cause of hospitalization and serious respiratory illness in infants/young children. The objectives of this study were to (1) identify important RSV-related signs of illness in infants that were observed by the parent/caregiver of the child and (2) assess content validity and usability of the Pediatric RSV Electronic Severity and Outcomes Rating System (PRESORS) to monitor signs of RSV-related illness.

Methods: Review of medical literature identified signs of pediatric RSV-related illness in PRESORS. Semi-structured interviews with caregivers of infants (0-24 months of age) hospitalized with laboratory-confirmed RSV infection (in the two months prior to recruitment) were conducted to spontaneously elicit signs and impacts of the infant's illness from caregiver observations. Caregivers completed PRESORS using a "think-aloud" protocol to confirm comprehension, relevance, and usability of the smartphone application. Verbatim transcripts were analyzed using thematic analysis methods and Atlas.ti software.

Results: Interviews with 21 caregivers confirmed PRESORS captured 23/26 signs caregivers spontaneously reported. Cough, difficulty breathing, problems sleeping, and reduced feeding/drinking were the most worrying signs of severe RSV-related illness described. Cognitive debriefing indicated that caregivers: understood the wording of all PRESORS items and response options (except how to count heartbeats), recall periods were appropriate, and the PRESORS smartphone application was easy to use. Minor changes to enhance content validity were identified.

Conclusions: In-depth interviews confirmed content validity and usability of the PRESORS by caregivers of infants with RSV. Next steps are to assess the revised PRESORS in clinical studies and evaluate its measurement properties.