Translation and psychometric performance of the Serbian version of the Sarcopenia Quality of Life (SarQoL®) questionnaire

Abstract

Introduction/Objective. The Sarcopenia Quality of Life (SarQoLR) questionnaire is a patient-reported outcome measure specific to sarcopenia. The objective was to translate the SarQoLR questionnaire from English into Serbian and to investigate its psychometric performance. Methods. A five-stage forward-backward methodology with pre-test was used to translate the questionnaire. The validation sample in this study consisted of elderly, community-dwelling volunteers of both sexes. Three methods were used to screen for and diagnose sarcopenia: the SARC-F questionnaire (high/ low risk), low handgrip strength [probable sarcopenia in the European Working Group on Sarcopenia in Older People (EWGSOP2) algorithm], and the complete EWGSOP2 criteria. We investigated the questionnaire’s discriminative power, internal consistency, construct validity, and floor and ceiling effects. Results. The SarQoLR questionnaire was translated into Serbian. The validation study included 699 participants. In total, 200 participants were considered to be at high risk of sarcopenia by the SARC-F, 84 were diagnosed with low handgrip strength and 12 were confirmed to be sarcopenic. We did not find significantly lower overall QoL scores using the EWGSOP2 criteria (60.31 vs. 64.60; p = 0.155). We did find lower scores for the probably sarcopenic group (52.80 vs. 65.50; p < 0.001) and the high-risk group (50.91 vs. 69.02; p < 0.001). The Cronbach’s α coefficient was 0.87, indicating a high internal consistency. Construct validity was adequate, with 75% of hypotheses on expected correlations with the SF-36 and EQ-5D questionnaires confirmed. No floor or ceiling effects were observed. Conclusion. We successfully translated the SarQoLR into Serbian, and showed that it is a valid tool for measuring QoL in the community-dwelling elderly.

Keywords

• sarcopenia
• quality of life
• sarqol
• validation