Systematic Literature Reviews of Health-State Utility Values, Costs, and Healthcare Resource Use in Duchenne Muscular Dystrophy.

Background: Duchenne muscular dystrophy (DMD) is a rare, X-linked inherited disorder starting in early childhood, characterized by progressive muscle loss and weakness, causing disability, loss of ambulation, and cardiopulmonary failure. Economic modeling is required to assess cost-effectiveness of new DMD therapies, but there are challenges from limitations and variations in currently available data. Objective: To assess the burden of DMD on patients, caregivers and healthcare systems, identifying inputs for cost-effectiveness models to inform economic assessments. Methods: Two systematic literature reviews (SLRs) were conducted. One SLR was performed to identify health state utility values (HSUV, original date 2019 with a 2023 update) and another to identify and cost data (original date 2023). Both SLRs were updated in 2024. Databases searched included Embase, MEDLINE, Centre for Reviews and Dissemination and EconLit, with additional hand-searching. PRISMA guidelines were followed. For each SLR, title/abstract and full-text screening were performed by two independent reviewers before data extraction. Validated quality assessment tools were used. Results: Across both SLRs, the burden increased as DMD progressed from early to late stages, indicated by decreasing HSUVs and increasing healthcare resource use and costs. The results highlighted large increases in burdens between early nonambulatory and late nonambulatory DMD in studies using the typical 4-state progression model. Recent publications using an 8-stage natural history model reported gradual increases in burden. There was heterogeneity between studies and a lack of long-term data in both SLRs. Discussion: The results highlighted the complex nature of progressive DMD, with heterogeneity and lack of long-term data across the studies. The findings suggest that HUI-3 may be the preferred tool for HSUV measurement in DMD, and the 8-stage natural history model may be preferable to typical 4-state models of DMD progression, to account for the observed heterogeneity and non-linear progression of this rare disease. Conclusions: These data indicate that the burden on patients, caregivers, and healthcare systems increases as DMD progresses. A wide range of inputs for economic modeling were identified, including insights into the way that the stages of DMD should be modeled to accurately reflect progression.