Spanish translation, cultural adaptation and validation of the SarQoL®: a specific health-related quality of life questionnaire for sarcopenia

Background In 2015, a specific health-related quality of life questionnaire for sarcopenia, SarQoL (R), was developed and validated in French. Since then, SarQoL (R) has been adapted and validated in different languages. We prepared a translation, cultural adaptation and validation of the psychometric properties of the SarQoL (R) into Spanish. Methods A cross-sectional study with 86 participants. The translation and adaptation followed international guidelines with two direct translations, a synthesized version of the direct translations, two reverse translations, consensus by an expert committee of a pre-final version, pre-test by end users and final version. The discriminative power (logistic regression analyses), construct validity (Pearson and Spearman ' s correlation), internal consistency (Cronbach ' s alpha coefficient), test-retest reliability (intraclass correlation coefficient) and ceiling and floor effects were analyzed. Results The Spanish version showed good construct validity (high correlation with comparable domains of the SF-36), high internal consistency (Cronbach's alpha coefficient: 0.84) and excellent test-retest reliability (ICC: 0.967, 95%, CI 0.917 - 0.989). However, it had no discriminative power between sarcopenic and non-sarcopenic participants defined with the EWGSOP and FNIH diagnostic criteria of sarcopenia. It did show discriminative power between patients with decreased vs normal muscle strength (54.9 vs. 62.6, p 0.009) and low vs. normal physical performance (57.3 vs. 70.2; p 0.005). No ceiling or floor effect was found. Conclusions The Spanish version of SarQoL (R) has similar psychometric properties to those of the original version of the instrument. It did not discriminate between sarcopenic and non-sarcopenic patients diagnosed according to the EWGSOP or FNIH criteria, but it did with those with low muscle strength and low physical performance.

Automated summary

This study translated and culturally adapted the SarQoL(R) questionnaire for sarcopenia into Spanish and validated its psychometric properties. The Spanish version of SarQoL(R) demonstrated good construct validity, high internal consistency, and excellent test-retest reliability. However, it did not have discriminative power in differentiating between sarcopenic and non-sarcopenic participants based on specific diagnostic criteria. It did, however, show discriminative power in differentiating between patients with low muscle strength and low physical performance.