Validation Of A Of Self-Reported Measure Of Physical Capacity In The Context Of Chronic Cardiovascular And Pulmonary Diseases

Background: The assessment of physical capacity (PC) is relevant to estimate prognosis and guide therapeutics for patients with chronic cardiopulmonary disease. The Veterans Specific Activity Questionnaire (VSAQ) is a self-reported tool designed to assess perceived physical capacity in METs according to a given patient’s level of physical activity limited by symptoms. The purpose of this study was to examine the validity of the score of the French-Canadian version of the VSAQ among patients suffering from cardiovascular symptoms and chronic pulmonary diseases. Methods: A total of 140 subjects referred for treadmill testing (TT group) and 134 patients with pulmonary hypertension or interstitial lung disease (PD group) were enrolled. Criterion validation was verified in the TT group by level of agreement (Bland-Altman coefficient) between the VSAQ and the workload estimated by the gold standard to assess PC, the maximal treadmill test (MTT). Convergent validation was tested using correlations between the VSAQ score and physical capacity (MTT and 6-min walking test - 6MWT); practice of physical activity (Godin-Shephard Leisure-Time Physical Activity Questionnaire-GSLTPAQ); pulmonary function (forced vital capacity- FVC) and quality of life (Minnesota living with Heart Failure Questionnaire-LHFQ and SF-12). Partial correlation coefficients were adjusted for sex, age, BMI and education. Results: The mean bias between VSAQ and estimated METs was -1.54 with limits of agreement (CI 95%) of 3.71 to -6.79 METs, being constant around all MET levels. Significant correlations (p <0.05) between the VSAQ score in the TT sample were 0.65 with MTT, 0.20 with the GSLTPAQ; -0.36; -0.39 and -0.29 with the LHFQ total score, physical and emotional domains. Significant correlations (p <0.05) for the PD sample were: 0.58 with 6MWT; 0.43 with FVC (interstitial lung disease only); 0.31 with GSLTPAQ; and 0.65 and 0.24 with SF-12 physical and emotional components. Conclusion: The VSAQ French-Canadian version demonstrated acceptable criterion and convergent validation among two different groups of chronic disease patients. Its utilization by the nurse during routine clinical follow-up of these patients could be helpful to guide functional evaluations and interventions.