[Development, reliability, and validity of a treatment-related quality of life scale for Chinese patients with...

Objective: To develop a treatment-related quality of life scale for Chinese patients with multiple myeloma (MM) and to test its reliability and validity. Methods: The initial scale was constructed through a literature search, Delphi expert correspondence, and cognitive testing. This study conducted a preliminary survey of 379 patients with MM and a formal survey of 865 patients from the hematology departments of 155 hospitals nationwide from February 2024 to March 2024. The final scale was obtained after conducting item analysis and reliability and validity tests on the initial scale. Results: The constructed scale contains 36 items covering six domains: physiological, psychological, social, treatment side effects, general health, and others. In the preliminary survey, the Cronbach's alpha coefficient of each item ranged from 0.597 to 0.939, and the test-retest reliability was 0.747 (P<0.001). Exploratory factor analysis extracted eight common factors with a cumulative variance contribution of 60.058%. In the formal survey, the Cronbach's alpha coefficient of each item ranged from 0.484 to 0.930, and the test-retest reliability was 0.835 (P<0.001). Confirmatory factor analysis revealed a comparative fit index of 0.750, a root-mean-square error of approximation of 0.090, and a root-mean-square residual of 0.067. Conclusion: The treatment-related quality of life scale for Chinese patients with MM designed in this study exhibited good reliability and validity, reflecting the impact of treatment on the quality of life of patients. This scale can provide a reference to clinicians for assessing the disease status of patients.