Abstract
Recently, SarQoL((R)) (Sarcopenia and Quality of Life), a quality of life (QoL) questionnaire specific to sarcopenia, was successfully developed. For practical reasons, there is a great interest in validating this questionnaire in other populations. The aim of this cross-sectional study was to translate and adjust the SarQoL((R)) into Polish and to standardize the validity of this method for the assessment of sarcopenic individuals in Poland with regard to psychometric properties. The English version was used for the translation process. A total of 106 community-dwelling Caucasian subjects aged 73.3 +/- 5.94 years (65.1% females) were studied, with 60 participants being diagnosed sarcopenic. The translation and cross-cultural adaptation was carried out in five phases according to specific standard guidelines. There were no major linguistic issues in the translation process. The data confirmed a good discriminant validity, i.e., significantly lower scores for all domains (reduced global QoL in sarcopenic subjects compared to non-sarcopenic ones; 54.9 +/- 16.5 vs. 63.3 +/- 17.1, p = 0.013), and high internal consistency (Cronbach's alpha coefficient was 0.92). The significant correlation of the SarQoL((R)) scores with those of other questionnaires (SF-36v2((R)) Health Survey and EuroQoL-5-Dimension) that are supposed to have similar dimensions indicated the consistent construct validity of the SarQoL((R))-PL questionnaire. No floor/ceiling effects were found. An excellent agreement was found between the test and the re-test (intraclass coefficient correlation (ICC): 0.99). The first Polish version of the SarQoL((R)) questionnaire is valid and consistent and therefore may be used with reliability for clinical and research purposes regarding QoL assessment of sarcopenic individuals. However, further research, in particular prospective studies, is needed to determine potential limitations and the suitability of the new tool for the Polish scenario and specificity.