Validation of Instrument to Assess Hemophilia-Related Distress

Introduction: In chronic diseases such as diabetes and cancer, disease-related distress is known to impact disease management and health outcomes (Barry et al. J Health Psychol 2019). We sought to develop and validate an instrument to measure hemophilia-related distress (HRD). Methods: Using themes raised during qualitative interviews, questions were written to assess HRD. Questions were revised after review by clinicians and patient focus groups. The final formatted HRD instrument comprised 24 Likert scale questions (response level 0-5) plus a numerical rating of current distress on a 1-10 scale. The HRD total score is the sum of all domain scores and could range from 0-120 with lower scores indicating less HRD. Adults (≥18 years) with hemophilia receiving care at one of two hemophilia treatment centers were recruited to participate in the validation study. After informed consent, participants reported demographic and clinical information then completed the HRD instrument and questionnaires that measured characteristics similar to HRD including: the National Cancer Center Network (NCCN) Distress Thermometer, Kessler 6+ (K6), Patient Health Questionnaire (PHQ-9), Brief Pain Inventory (BPI), 5-level EuroQol-5D (EQ-5D-5L), Haem-A-Qol, Work Productivity and Activity Impairment Questionnaire plus Classroom Impairment (WPAI), and PROMIS-29. Analysis included factor analysis and assessment of internal consistency using Cronbach's α, construct validity using Pearson's correlation coefficient and discriminant validity by comparing subgroups of patients. A subset of participants electronically completed the HRD instrument a second time within 7 days of initial assessment. Test-retest reliability was assessed using an interclass correlation coefficient (ICC). Results: Among 130 enrolled participants, 126 completed the HRD instrument in a median time of 5.4 minutes (Q1;Q3 3.5;14.4) with overall HRD scores ranged from 2-83 (median=31.5). Subject characteristics are shown in table 1. Factor analysis of 1-5 domains was undertaken with final selection of a 4-domain instrument (RMSEA 0.057 [90% CI 0.041,0.072]; CFI 0.97). The 4 domains are (# of items, Cronbach's α): Hemophilia Management Concerns (7 items, 0.81); Financial Concerns (3 items, 0.81); Perceived Self-efficacy (3 items, 0.79); Daily Function Concerns (7 items, 0.85). Assessment of convergent validity (table 2) demonstrated a moderate correlation (>0.60) of the HRD total score with the NCCN Distress Thermomete