Validity and reliability of Sarcopenia Quality of Life® Indonesia questionnaire in sarcopenic patients

Background: Sarcopenia significantly impairs quality of life (QoL). The Sarcopenia Quality of Life® (SarQol®) questionnaire provides a sarcopenia-specific instrument for the assessment of QoL. The aim of this study was to cross-culturally adapt the SarQol® to an Indonesian language questionnaire and to confirm its validity and reliability as a tool to measure QoL in Indonesian-speaking elderly patients with sarcopenia. Methods: This cross-sectional study translated and cross-culturally adapted the SarQol® questionnaire, followed by evaluating the psychometric properties of the final cross-culturally adapted SarQol® Indonesia questionnaire. Results: Fifty-nine elderly Indonesian subjects (29 sarcopenic and 30 nonsarcopenic) with a mean age of 72.2 ± 6.3 years were included in this study. SarQol® Indonesia questionnaire overall provides a good discriminative value [60.61 ± 14.34 vs. 73.60 ± 13.17, p = 0.001], good internal consistency (Cronbach's ⍺ coefficient = 0.896 and McDonald's ⍵ coefficient = 0.906, both with good correlation to the questionnaire individual domains), acceptable construct validity, and good test–retest reliability (intraclass correlation coefficient: 0.962 [95% confidence interval: 0.883–0.987]). Conclusions: The SarQol® Indonesia questionnaire provides a conceptual and literally equivalent questionnaire content to its original source with good discriminative value, good internal consistency, acceptable construct validity, and good test–retest reliability. The SarQol® Indonesia questionnaire is ready to be used to measure QoL in Indonesian elderly sarcopenic individuals.