Construction of a six-minute walk distance prediction formula for healthy adults in high-altitude region of China

Most existing prediction formulas for the six-minute walk distance (6MWD) are based on populations living at low altitudes, and their applicability to populations in high-altitude regions remains unclear. By measuring the 6MWD of healthy adults in high-altitude regions of China, this study aims to develop a 6MWD prediction formula suitable for this population and compare it with existing formulas. A total of 463 healthy subjects from high-altitude regions in China were enrolled and completed the standardized six-minute walk test. The dataset was randomly split into training and validation sets at a 7:3 ratio. A new prediction model was constructed using stepwise multiple linear regression in the training set, and its performance was assessed in the validation set via the coefficient of determination, root mean square error, and mean absolute error. Bland-Altman analysis was used to assess the prediction bias of published formulas. The mean 6MWD for all subjects was 548 ± 58.9 m and was significantly longer for men that for women (563.9 ± 67.5 m vs. 534.7 ± 46.8 m, P < 0.001). Two sex-specific prediction formulas were finally established. The existing formulas systematically overestimated the 6MWD of the study population. This study initially developed the first 6MWD prediction formula specifically for healthy individuals in high-altitude areas of China, and demonstrated that the existing prediction formulas are not applicable to this population. This finding holds significant clinical value and is expected to provide a more accurate reference for the assessment of cardiopulmonary function and disease management in high-altitude populations.