Validity and equivalence of the Portuguese version of the Veterans Specific Activity Questionnaire.

BACKGROUND The Veterans Specific Activity Questionnaire (VSAQ) has been used to individualize exercise testing (ET) and to indirectly assess cardiorespiratory fitness (CRF) in epidemiological studies. Nevertheless, there is no validated Portuguese version. OBJECTIVE To verify the criterion-related validity and the measurement equivalence of a Portuguese version of VSAQ in 95 individuals, 8 women (aged 69 ± 7 years) referred to ET. METHODS The subjects performed a cardiopulmonary test with incremental to maximal exercise on a cycle ergometer. The correlation between VSAQ score and Maximum Measured and Estimated METs was compared to results from other studies. The VSAQ Nomogram was calculated and its results were compared to CRF real values by linear regression. Limits of concordance and mean differences (biases) were assessed according to the Bland Altman methodology. RESULTS The VSAQ scores were significantly correlated to the Measured METs (r = 0.64) and Estimated METs (r = 0.67), results that were equivalent to those obtained by the original versions. The VSAQ Nomogram presented multiple R of 0.78 (Measured MET) and 0.80 (Estimated MET). However, the Nomogram seems to have underestimated CRF values greater than 6 METs. CONCLUSION The VSAQ version confirmed its validity and equivalence to the original version, especially when evaluating individuals with coronary heart disease and older adults.