Validation of 6-Minute Walk Test and Development of VO Prediction Equation in the Elderly

PURPOSE Cardiorespiratory fitness is closely related to cardiovascular and chronic diseases and is an important predictor of mortality. Despite the significance of cardiorespiratory fitness, currently, a lack of research exists that validates the effectiveness of the 6-minute walk test, specifically in the Korean population. Therefore, the purpose of this study was to verify the validity of the 6-minute walk test for Korean older individuals and to develop a maximum oxygen consumption (VO2max) prediction equation. METHODS A total of 167 participants were included in the final analysis, after excluding 33 of the 200 participants. Moreover, VO2max was measured by performing a submaximal exercise test on a treadmill, and the total distance and heart rate were measured using a 6-minute walk test. Pearson's correlation coefficient was calculated to verify the criterion validity between VO2max and total distance in the 6-minute walk test. To develop a VO2max prediction equation, multiple regression analysis was conducted and cross-validation of the developed prediction equation was confirmed. RESULTS The correlation coefficient between VO2max and the 6-minute walk test was 0.575 (p<.001). The adjusted R2 of the VO2max prediction equation using the 6-minute walk test was 0.449 (p<.001). The difference between the predicted VO2max and measured VO2max was 1.184±1.331 mL/kg/min, and the correlation coefficient was 0.594 (p<.001). CONCLUSION The developed prediction equation consisted of explanatory variables that can be measured easily and were practical in the field. As entry into a post-aged society is imminent, managing older adult's physical fitness has become a significant issue. In the future, if the validity verification is performed with a large number of people, the prediction formula developed in this study will be useful.