Reliability and concurrent validity of the Acti’MET® calculator: A new tool to assess physical activity in cardiac rehabilitation

Abstract

ObjectiveWe created a tool for assessing physical activity (PA), the Acti’MET® calculator, to quickly estimate weekly energy expenditure. This study aimed to assess the metrological properties of the tool in cardiac rehabilitation (CR). MethodsTwo examiners evaluated the reliability and concurrent validity of the tool with cardiac patients. The validity of the tool was assessed by comparison with other classical methods for measurement of PA such as the Dijon Physical Activity Score (PAS) and the International Physical Activity Questionnaire (IPAQ) score, the 6-min walk test (6MWT) and the cardiopulmonary maximal exercise test. Correlation was assessed by Pearson or Spearman correlation analysis. ResultsFor the 36 cardiac patients (mean age 55±11 years, 24 men), inter-rater and intra-rater reliabilities were strong: r=0.87 and r=0.98, respectively, both P<0.0001. We found a strong correlation of the Acti’MET® score with the IPAQ score (r=0.88, P<0.0001), moderate correlation with the PAS (r=0.39, P<0.05) and 6MWT (r=0.54, P<0.01), and no correlation with peak power output. ConclusionThe Acti’MET® calculator is reliable, valid and easy to use for assessing PA in CR. This tool seems to well reflect the weekly PA, unlike the PAS, which evaluates PA on a yearly basis.