Derivation of Reference Equation for 6-Minute Walk Test in Healthy North Indian Young Adult Males and Females Aged 20-40 Years

Background Six-min walk test (6MWT), is a globally recognised assessment tool for functional capacity. It is a clinical tool to determine the prognosis and effectiveness of any therapeutic/medical intervention. However, previous reference equations for the six-minute walk distance (6MWD) have failed to accurately predict the 6MWD due to variations in population. Objective The aims of this study were 1) to measure 6MWD in healthy North Indian young adult males and females, 2) to compare the established 6MWD with the previous studies, and 3) to develop a regression equation for healthy north Indian males and females. Material and Method 200 healthy subjects (males=116, females=84) between 20-40 years of age were enrolled after screening. A standardized 6MWT was administered and distance was measured. Results The mean (SD) distance of 6MWT was 626.0864.49 m. The previous published equation did not correctly predict the distance in north Indian population. Gender, height, age, physical activity score (PAS) and socioeconomic status (SES) showed a significant relationship with the 6MWD which Predicted 6MWD 160.903 - 1.640*Age (years) + 2.540*Height (cm) 3.708*BMI (kg/m2) + 29.098*PAS + 6.931*SES + 34.815*Gender (where female = 1, male = 2) which explained around 62.5 % of variance of 6MWD, whereas Gender, height and age Predicted 6MWD 188.633 2.902*Age (years) + 3.257* Height (cm) + 26.780*Gender (where female = 1, male = 2) which explained 54.7 % of variance of 6MWD. Conclusion Published equations are not valid for predicting the 6MWD in healthy north Indian young adult males and females.