Developing And Validating Equations To Predict O-2 Peak From The 6mwt In Childhood All Survivors

Introduction: The 6-Minute Walking Test (6MWT) is a safe, standardized and well utilized method to assess the functional capacity. Recently, it was reported that the published prediction equations cannot accurately predict a valid maximal oxygen consumption (O-2 peak) value in cancer survivors. Thus, the aim of this study was to establish and to validate a new equation based on the 6MWT to predict O-2 peak in childhood acute lymphoblastic leukemia (ALL) survivors. Methods: A total of 200 childhood ALL survivors were enrolled in this study, among which 168 participants underwent a cardiopulmonary exercise test and a 6MWT to assess their functional capacity and their cardiorespiratory fitness. In addition, participants completed a physical activity questionnaire. Participants were randomly divided in two groups to establish the equations (n = 118 (70%)) and to validate it (n = 50 (30%)). Multiple linear regression analyses were used to determine a new prediction equation for O-2 peak from 6MWT using clinical and specific variables related to the disease. The accuracy in between O-2 peak measured and O-2 peak predicted were assessed using the Bland and Altman method. Results: The new establish clinical O-2 peak equation is: O-2 peak (mL.kg(-1).min(-1)) = (-0.283*age(years)) - (0.099*weight(kg)) + (0.071*6MWD(meters)) -(0.135*HR end(bpm)) + 22.789 with a mean bias of 2.67 mL.kg(-1).min(-1) (95% CI (-9.64 to 14.98)). The new establish disease-specific O-2 peak equation is: O-2 peak (mL.kg(-1).min(-1)) = (-0.236*age(years)) - (0.094*weight(kg)) -(0.120*HR end(bpm)) + (0.067*6MWD(meters)) + (0.065*MVLPA(min/day)) - (0.204*DT(years)) + 25.145 with a mean bias of 2.51 mL.kg(-1).min(-1) (95% CI (-9.98 to 15.01)). Conclusion: This is the first study that predicted O-2 peak from a 6MWT using clinical and specific variables related to the disease of childhood ALL survivors. The availability of these newly established O-2 peak equations makes them an accurate tool to provide a better follow-up and better adapted physical training for survivors. We invite researchers to use our assessment procedures for their further studies.