OBJECTIVES: Cross-sectional studies have documented profound impacts of DMD on utility values, however data on how utilities change over time are unavailable. The objective was to examine changes in utility scores over 12 months, accounting for patients’ baseline health state and among those experiencing key functional transitions in DMD.

METHODS: Individuals with DMD or their caregivers completed the EQ-5D and HUI instruments at baseline and 12 months later. Mean (standard deviation [SD]) changes in EQ-5D, HUI-3 and HUI-2 utility values were estimated overall (for patients and caregivers together) according to baseline health state (early ambulatory, late ambulatory, early non-ambulatory, and late non-ambulatory). The frequency of key functional transitions (declines in lower or upper limb function, development of cardiomyopathy, or need for daytime ventilation) were documented. Linear mixed regression models estimated changes in utility scores.

RESULTS: One-hundred fifty-five participants completed baseline and 12-month measures. Mean (SD) patient age was 15.4 (6.7) years and 32.9% were ambulatory. Mean (SD) utility change over 12 months was -0.01 (0.16; EQ-5D), -0.02 (0.14; HUI-3), and -0.01 (0.11; HUI-2). When stratified by baseline health state, trends were similar. For 17 patients (11.0%) who experienced declined lower limb function, a significant reduction in utility was observed (-0.09 [0.03; EQ-5D], -0.19 (0.05; HUI-3], and -0.16 [0.03; HUI-2]). Development of cardiomyopathy (n=16; 10.3%) was associated with a significant decline on the HUI-3 (-0.12[0.05]) and HUI-2 (-0.08[0.03]) but not EQ-5D (-0.01[0.05]). Upper limb functional loss (n=5; 3.2%) and progression to daytime ventilation (n=3; 1.9%) were infrequent, hindering observations of utility changes with these transitions.

CONCLUSIONS: This longitudinal assessment in DMD found that, while individual utility varied, there was little change in mean utility over 12 months. However, key functional transitions were associated with significant changes in utility. These findings contribute to understanding how functional changes are related to changes in utility in DMD.