Validation of the Persian version of the sarcopenia-specific quality of life questionnaire (SarQoL (R)-IR)

Background The sarcopenia quality of life (SarQoL)(R) questionnaire is a specific tool to measure QoL in sarcopenia. The aim of this study was to validate the SarQoL (R) questionnaire for evaluation of sarcopenia-related quality of life in Iranian community-dwelling older adults. Methods Validity (discriminative power, construct validity), reliability (internal consistency, test-retest reliability), and floor/ceiling effects of SarQoL (R) questionnaire were evaluated in the current study. Moreover, the SarQoL (R) questionnaire was compared with the Short-Form 36-item (SF-36) and the EuroQoL 5-Dimensions (EQ-5D) questionnaires. Results Among 501 community-dwelling older adults, 128 elderly participants (including 88 sarcopenic individuals) were recruited for validation. Participants with sarcopenia had lower quality of life than non-sarcopenic individuals (Total Score: 39.37 +/- 7.45 vs. 65.09 +/- 7.85, p < 0.001). Also, the findings demonstrated a high internal consistency (Cronbach's alpha of 0.881), excellent test-retest reliability (ICC = 0.995, 95% CI 0.990-0.998), and no floor/ceiling effect of SarQoL (R) questionnaire. Conclusion This is the first study to confirm the reliability and validity of the Persian version of the SarQoL (R) for the measurement of quality of life among Iranian sarcopenic older adults.