title: Reference equations for 6-min walk test in healthy Indian subjects (25-80 years).
abstract: BACKGROUND
  Six-min walk test (6MWT), a simple functional capacity evaluation tool used globally to determine the prognosis and effectiveness of any therapeutic/medical intervention. However, variability in reference equations derived from western population (due to racial and ethnicity variations) hinders from adequate use of 6MWT clinically. Further, there are no valid Indian studies that predict reference values for 6-min walk distance (6MWD) in healthy Indian normal.
  
  
  OBJECTIVE
  We aimed for framing individualized reference equations for 6MWT in healthy Indian population.
  
  
  METHODS
  Anthropometric variables (age, weight, height, and body mass index (BMI)) and 6-min walk in a 30 m corridor were evaluated in 125 subjects (67 females) in a cross-sectional trial.
  
  
  RESULTS
  6MWD significantly correlated with age (r = -0.29), height (r = 0.393), weight (r = 0.08), and BMI (r = -0.17). The gender specific reference equations for healthy Indian individuals were: (1) Males: 561.022 - (2.507 × age [years]) + (1.505 × weight [kg]) - (0.055 × height [cm]). R (2) = 0.288. (2) Indian females: 30.325 - (0.809 × age [years]) - (2.074 × weight [kg]) + (4.235 × height [cm]). R (2) = 0.272. Though the equations possess a small coefficient of determination and larger standard error estimate, the former applicability to Indian population is justified.
  
  
  CONCLUSIONS
  These reference equations are probably most appropriate for evaluating the walked capacity of Indian patients with chronic diseases.
authors.affiliation: Department of Pulmonary Medicine, Peelamedu Samanaidu Govindarajulu Hospitals, Peelamedu, Coimbatore, Tamil Nadu, India.
authors.forename: Ramanathan
authors.initials: R
authors.lastname: Palaniappan Ramanathan
authors.affiliation: Department of Pulmonary Medicine, Peelamedu Samanaidu Govindarajulu Hospitals, Peelamedu, Coimbatore, Tamil Nadu, India.
authors.forename: Baskaran
authors.initials: B
authors.lastname: Chandrasekaran
keywords: 6-min walk distance; Indian population; functional capacity; reference value; walk test