Cross-cultural equivalence of three scales used to estimate cardiorespiratory fitness in the elderly

This study aimed at establishing the cross-cultural equivalence of scales used to evaluate physical activity level and measure cardiorespiratory fitness, for further application in elderly subjects. Three scales were identified after systematic review: Veterans Physical Activity Questionnaire (VSAQ), Rating of Perceived Capacity (RPC), and Physical Activity Rating (PA- R). The model proposed by Herdman et al. was applied to analyze equivalence. Test-retest reliability was calculated in a sample of 12 elderly subjects (74.5 +/- 3.5 years) using Lin's concordance coefficient and intraclass correlation coefficient. Good reproducibility was detected in all scales except RPC. Due to the small sample size, hardly any conclusions can de drawn, but the results point to the need for changes in the original scale's structures. The findings also suggest the adequacy of the scale's Portuguese-language version, although further validity studies appear to be necessary.