Background: In a prior study, we developed and validated the Duchenne Muscular Dystrophy-Health Index (DMD-HI) and the Duchenne Muscular Dystrophy Caregiver Reported-Health Index (DMDCR-HI). These regulatory-grade instruments are designed to detect clinically meaningful changes in DMD disease burden during industry trials.
Objective: To conduct a 2-year longitudinal study of individuals with DMD and caregivers of individuals with DMD using the DMD-HI and DMDCR-HI.
Methods: Individuals with DMD ages 11 and older are completing the DMD-HI, the Peds-QL DMD Module, an instrument preference survey, and a demographic questionnaire at baseline, 6, 12, 18, and 24. Caregivers of individuals with DMD ages 0-21 are completing the DMDCR-HI, an instrument preference survey, and a demographic questionnaire. Caregivers of individuals with DMD are completing Generic Peds-QL or the Peds-QL DMD Module based on the patient’s age. Data will be used to determine: 1) How disease burden changes in DMD overtime; 2) The minimal clinically important difference (MCID) of the DMD-Health Indices; 3) Factors associated with faster progression of disease; and 4) Participant instrument preferences.
Results: To date, thirty-six individuals with DMD and 92 caregivers of individuals with DMD have been enrolled for this study. Individuals with DMD reported a mean age of 21.8 years with an average disease duration of 16.6 years. Caregivers, predominantly mothers, reported on behalf individuals with DMD with a mean age of 12.3 years old. Over 70% of caregivers reported that the individual for whom they care has a moderate to severe disability level. All six-month assessments will conclude by January 2025.
Conclusions: Multifactorial disease burden in DMD can be quantified and longitudinally monitored using the DMD-HI and DMDCR-HI in the context of a clinical trial. Additional performance data regarding these instruments and knowledge of how disease burden changes in select DMD populations is forthcoming.