Reliability and validity tests of the Chinese version of the Geriatric Locomotive Function Scale (GLFS-25) in tumor survivors

Objective: To evaluate the reliability and validity of the Chinese-translated Geriatric Locomotive Function Scale (GLFS-25) for the assessment of locomotive syndrome (LS) in individuals surviving malignancies. Methods: 393 tumor survivors at a general hospital in China were recruited. The Chinese version of GLFS-25 was utilized to conduct a cross-sectional survey to ascertain the tool's efficacy in measuring LS in this cohort. The scale's validity was examined through content, structural and discriminant validity assessments, while its reliability was investigated by determining the internal consistency (via Cronbach's alpha coefficient) and test-retest reliability (via intragroup correlation coefficient, ICC). Results: The Chinese-adapted GLFS-25 demonstrated a robust scale-level content validity index of 0.94, while item-level content validity indices ranged from 0.83 to 1.00 across individual items. The suitability of the scale for structural validity assessment was confirmed via exploratory factor analysis, yielding a Kaiser-Meyer-Olkin measure of 0.930 and a significant Bartlett's test of sphericity (chi(2) = 3217.714, df = 300, P < 0.001). Subsequent confirmatory factor analysis (CFA) extracted four distinct factors: Social Activity Engagement, Daily Living Ability, Pain Experience and Physical Mobility. These factors accounted for 72.668 % of the variance, indicating substantial construct validity for measuring LS among this population. CFA supported the model's fit with the following indices: chi(2)/df = 1.559, RMSEA = 0.077, GFI = 0.924, CFI = 0.941, NFI = 0.919, and TLI = 0.933. The factor loadings for the four factors ranged from 0.771 to 0.931, indicating the items corresponding to the four factors effectively represented the constructs they were designed to measure. The correlation coefficients among the four factors were between 0.306 and 0.469, all lower than the square roots of the respective AVEs (0.838-0.867). This suggests a moderate correlation among the four factors and a distinct differentiation between them, indicating the Chinese version of the GLFS-25 exhibits strong discriminant validity in Chinese tumor survivors. Reliability testing revealed a high Cronbach's alpha coefficient for the overall scale at 0.961, with the subscales yielding coefficients of 0.751, 0.836, 0.930, and 0.952. The overall ICC was determined to be 0.935, with subscale ICCs ranging from 0.857 to 0.941, reinforcing the scale's reliability in this context. Conclusions: The Chinese version of the GLFS-25 exhibits strong reliability and validity for the assessment of LS in tumor survivors. It may serve as a diagnostic tool for LS, contributing to the prevention and management of musculoskeletal disorders and enhancing the prognosis for this patient population.