Content validation of observer-reported sickle cell pain diaries (SCPD-CS and SCPD-CN): results from interviews with caregivers

Abstract Background Patients with sickle cell disease (SCD) experience daily pain and acute episodes known as sickle cell pain crises (SCPCs). The Sickle Cell Pain Diary - Caregiver Report (SCPD-C) is an observer-reported diary for use by caregivers of children ages < 12 years with SCD. This study reports on the content validity of the SCPD-C. Methods The SCPD-C was developed based on a literature review, measurement expert input, and a patient advisory board including clinicians. Three rounds of interviews (including both concept elicitation and cognitive debriefing methodologies) were conducted with caregivers of children with SCD aged < 12 to evaluate the content validity of the SCPD-C. Results Across three rounds of interviews, caregivers confirmed concepts in the SCPD-C and described observed impacts that were important and were added. Overall, caregivers evaluated the SCPD-C as easy to understand, with some minor adaptations for clarity. Additionally, the diary was split into two versions based on the child’s age and school enrollment status (SCPD-CS for school-aged and SCPD-CN for non-school age children). Conclusions Caregivers provided valuable input that led to important additions and changes to the measures. The SCPD-CS and SCPD-CN are appropriate and fit-for-purpose observer-reported outcome measures of SCPC-related pain frequency and severity, and the impacts on health-related quality of life.