Psychometric Properties of the Chinese Version of the Sarcopenia and Quality of Life, a Quality of Life Questionnaire Specific for Sarcopenia.

A quality of life questionnaire specific to sarcopenia (SarQoL®) was successfully developed. There is a huge demand for translation and validation in Chinese. The aim of this study was to translate the SarQoL® into Chinese and investigate its psychometric properties. The translation and cross-cultural adaptation process recommended by the developers of the initial questionnaire was followed. A total of 159 participants were investigated. The translation process consists of five steps: (1) two bilinguals independently translate initial English to Chinese; (2) synthesize the two translations into one; (3) backward translations; (4) expert committee review and (5) test of the pre-final version. The validation consists of three parts: (1) validity (discriminative power, construct validity); (2) reliability (internal consistency, test-retest reliability) and (3) floor and ceiling effects. There was no difficulty in translation process. Regarding the validity, good discriminant validity {quality of life for sarcopenic subjects [35.56 (29.73-42.70)] vs. non-sarcopenic ones [73.22 (60.09-82.90)], p < 0.001} and consistent construct validity [high correlations (spearman's r) of SarQoL® with generic Short Form-36 version 2 questionnaire (0.250 to 0.824) and EuroQoL-5-Dimension questionnaire (- 0.114 to - 0.823)] were found in SarQoL®. Regarding reliability, high internal consistency (Cronbach's alpha coefficient was 0.867) and excellent test-retest reliability (intraclass coefficient correlation was 0.997, 95% CI 0.994-0.998) were found. No ceiling/floor effect was reflected. A valid SarQoL® questionnaire is now available for Chinese population. It can provide a better understanding of the sarcopenia disease burden and serve as a therapeutic outcome indicator in research.