Reference equations for the six-minute walk distance based on a Brazilian multicenter study

Area of Science:

• Physiology
• Biostatistics
• Public Health

Background:

• Establishing reference equations for the six-minute walking test (6 MWT) requires large sample sizes and consideration of influencing factors.
• The six-minute walking distance (6MWD) is a key functional measure in various clinical contexts.

Purpose of the Study:

• To determine the impact of anthropometric, demographic, and physiological variables on 6MWD in healthy Brazilians.
• To develop a predictive reference equation for 6MWD tailored to the Brazilian population.

Main Methods:

• A multicenter study involving 617 healthy subjects who completed two 6 MWTs.
• Measurement of anthropometric data (weight, height, BMI) and physiological responses (delta heart rate, perceived effort, oxygen saturation).
• Statistical analysis using quadratic regression and stepwise multiple regression to derive predictive equations.

Main Results:

• The average 6MWD was 586 ± 106 m, with males walking significantly farther than females (p<0.001).
• No significant regional differences in 6MWD were observed across Brazil.
• The best predictive model, including delta heart rate, explained 62% of the variability in 6MWD.

Conclusions:

• The derived equations, particularly the second model incorporating delta heart rate, are suitable for accurately predicting 6MWD in the Brazilian population.
• These reference equations can aid in the clinical assessment and interpretation of the 6 MWT in Brazil.