The Pediatric Quality of Life Inventory 4.0 Generic Core Scales (PedsQL 4.0 GCS) may not be a valid measure of health-related quality of life in patients with Duchenne muscular dystrophy (DMD), according to a new study published in Value in Health.
PedsQL 4.0 GCS is commonly used to measure health-related quality of life in patients with DMD. However, evidence of its psychometric properties in this patient population is limited.
In the present study, the investigators of the Cooperative International Neuromuscular Research Group explored the psychometric properties of the PedsQL 4.0 GCS using Rasch analysis. Rasch analysis is a modern psychometric method that is complementary to traditional approaches.
They recruited 329 patients with DMD aged 3 to 18 years, 75% of whom could still walk, from 20 centers across 9 countries. All patients completed the PedsQL 4.0 GCS.
The results showed that the most difficult items, expressing the greatest loss in health-related quality of life, were those associated with emotional well-being. These included being teased by other children, feeling sad, and not making friends. On the other hand, somatic disabilities such as being able to lift heavy objects, participate in sports, or run were the least difficult items.
The researchers concluded that the largest loss in health-related quality of life was captured by items associated with morbidity and disability. They said that these findings could help in the development of new scales measuring health-related quality of life in patients with DMD.
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The researchers also noted that based on Rasch analysis, the PedsQL 4.0 GCS administered to children and adolescents with DMD had significant psychometric issues. These included suboptimal targeting, poor item-trait interaction, disordered thresholds, differential item functioning, local item dependency, and multidimensionality.
The researchers concluded, “based on our analysis, it appears as if the PedsQL 4.0 GCS total score fails to successfully operationalize a quantitative conceptualization of [health-related quality of life] in patients with DMD and should be used with caution in this indication until further evidence is made available.”
Landfeldt E, Iff J, Henricson E; Cooperative International Neuromuscular Research Group Investigators. Rasch analysis of the Pediatric Quality of Life Inventory 4.0 Generic Core Scales administered to patients with Duchenne muscular dystrophy. Value Health. 2021;24(10):1490-1498. doi:10.1016/j.jval.2021.05.016