Validation of the Lithuanian version of sarcopenia-specific quality of life questionnaire (SarQoL^®)

Purpose: The aim of this study was to translate and culturally adapt the SarQoL^® questionnaire into Lithuanian and investigate its main psychometric properties. Methods: A cross-sectional study was performed on community-dwelling Lithuanian people aged ≥ 60 years. The revised criteria of the European Working Group on Sarcopenia in Older People were used. A forward–backward methodology was used for the translation, with a pre-test of the final version of the Lithuanian SarQoL^® questionnaire. Adjusted logistic regression analysis was used to compare sarcopenic and non-sarcopenic subjects. Internal consistency was determined using Cronbach’s alpha coefficient. The correlation of total score of the SarQoL^® and each domain of the Short-form General Health Survey (SF-36) and EuroQol-5D (EQ-5D) questionnaires was measured using Spearman’s correlations. Test–retest reliability was measured by the intraclass correlation coefficient. Results: The study was performed on 176 subjects. Fifty-eight subjects were diagnosed with sarcopenia. After adjustment for confounders, the total score of the SarQoL^® questionnaire was significantly lower for sarcopenic subjects compared to non-sarcopenic subjects (50.32 ± 8.58 vs 73.75 ± 13.51, p < 0.001). Cronbach’s alpha coefficient was 0.95. Neither floor nor ceiling effects were found. The SarQoL^® questionnaire revealed good correlation with similar domains of the SF-36 and EQ-5D questionnaires for convergent validity and weak correlations with different domains for divergent validity, confirming its construct validity. An excellent agreement between test and retest was found with an ICC of 0.976 (95% CI 0.959–0.986). Conclusions: Lithuanian version of the SarQoL^® is valid, reliable and consistent and could be used to assess quality of life in sarcopenic population.