Cross-cultural adaptation, validation, and reproducibility of the Alusti Test for the evaluation of physical and functional capacity in Brazilian older adults

INTRODUCTION: The Alusti Test is a Spanish scale for the multidimensional assessment of functionality in older adults. Nevertheless, it has not yet been cross-culturally adapted to the Portuguese language. OBJECTIVE: To carry out the cross-cultural adaptation of the Alusti Test in Brazilian Portuguese and to evaluate its psychometric properties. METHOD: The cross-cultural adaptation process into Brazilian Portuguese followed international recommendations. The test was applied to 100 individuals of both sexes aged 60 or over. Anthropometric, demographic data, education level, and Charlson Comorbidity Index were collected. The intraobserver reproducibility of the Alusti Test was evaluated twice, at an interval of 7-10 days (test-retest) using the intraclass correlation coefficient (ICC). Internal consistency was assessed using Cronbach's alpha coefficient. Finally, the validation of the Alusti Test in relation to the Barthel Scale and the Short Physical Performance Battery (SPPB) was verified using Spearman's correlation coefficient. RESULTS: The Brazilian version showed an excellent intraclass correlation coefficient (ICC=0.997 [0.996-0.998]). Internal consistency showed a Cronbach's alpha value of 0.96. There was a positive, strong and significant correlation between the Alusti Test and the Barthel Scale (r=0.93) and Short Physical Performance Battery (SPPB) (r=0.94); p<0.0001 for both. CONCLUSION: The Portuguese version of the Alusti Test has demonstrated both validity and reproducibility for assessing physical and functional capacity in older adults. This establishes it as a valuable tool for evaluating the geriatric population, contributing to improved understanding and management of their health and functional needs.