Reliability and validity of patient‐reported outcome instruments in US adults with hemophilia B and caregivers in the B‐HERO‐S study

OBJECTIVE: To assess the reliability and validity of six patient-reported outcomes (PRO) instruments for evaluating health-related quality of life in adults with mild-severe hemophilia B and caregivers of children with hemophilia B, including affected women/girls. METHODS: Adults with hemophilia B and caregivers completed separate online surveys containing several PRO instruments, which were administered to adult participants only (EQ-5D-5L, Brief Pain Inventory v2 Short Form, Hemophilia Activities List, and International Physical Activities Questionnaire), both adults and caregivers (Patient Health Questionnaire [PHQ-9]), or caregivers only (Generalized Anxiety Disorder 7-Item [GAD-7] scale). Construct validity and item-total correlation were assessed using Pearson product-moment correlation, internal consistency was assessed using Cronbach's alpha coefficient, and known-group validity was assessed by comparisons to self-reported characteristics based on the Kruskal-Wallis test. RESULTS: Patient-reported outcomes instruments generally showed satisfactory reliability for adults (n = 299) and caregivers (n = 150). In adults, PRO instruments generally showed high construct validity. Most PRO instruments showed expected significant differences among known groups for adults and caregivers. PHQ-9 and GAD-7 did not show significant differences among caregiver age groups. CONCLUSIONS: Patient-reported outcomes instruments administered in B-HERO-S demonstrated reliability and validity in the broader population of adults with hemophilia B and caregivers when including all severities and genders.