Validation of clinical frailty scale in Chinese translation

Background Identification of frailty is crucial to guide patient care for the elderly. The Clinical Frailty Scale (CFS) is a reliable, synthesis and clinical judgment-based tool. However, a validated Chinese version of CFS (CFS-C) is lacking. The aim of this study is to describe the translation process of CFS into traditional Chinese and to evaluate its reliability and validity in a geriatric study population in Taiwan. Methods This cross-sectional study recruited 221 geriatric outpatients aged 65 years or older at a medical center in Taipei, Taiwan. The Chinese version of CFS was produced following Brislin’s translation model. Weighted kappa for agreement and Kendall’s tau for correlation were used to assess inter-rater reliability (a subgroup of 52 outpatients) between geriatricians and one research assistant, and validity tests (221 outpatients) by comparing CFS-C with Fried frailty phenotype and Frailty Index based on Comprehensive Geriatric Assessment (FI-CGA). Correlation between CFS-C and other geriatric conditions were also assessed. Results The inter-rater reliability revealed moderate agreement (weighted kappa = 0.60) and strong correlation (Kendall’s tau = 0.67). For criterion validity, CFS-C categorisation showed fair agreement (weighted kappa = 0.37) and significant correlation (Kendall’s tau = 0.46) with Fried frailty phenotype, and higher agreement (weighted kappa = 0.51) and correlation (Kendall’s tau = 0.63) with FI-CGA categorisation. CFS-C was significantly correlated with various geriatric assessments, including functional disability, physical performance, hand grip, comorbidity, cognition, depression, and nutrition status. No significant correlation was found between CFS-C and appendicular muscle mass. Conclusions The CFS-C demonstrated acceptable validity and reliability in Chinese older adults in Taiwan. Development of CFS-C enhanced consistency and accuracy of frailty assessment, both in research and clinical practice.