Correlaciones entre el test de velocidad en 4 metros y el test de caminata en 6 min en enfermos respiratorios crónicos

Abstract

4-Meter Gait Speed Test (4MGST) a frailty test, is considered a surrogate for the 6-Minute Walk Test (6MWT) in COPD. However, it has not been investigated in other respiratory conditions. Over a year, we studied patients attending our Unit for evaluation with 6MWT, measuring the speed they achieved walking 4 m, 2 h before performing 6MWT. 162 patients (99 women) were studied; series’ mean values were: age 65 years-old; body weight, 73 kg; height, 158 cm and BMI, 29.4 kg/m². 36% of them had idiopathic pulmonary fibrosis, 17% GOLD IV COPD, 11% GOLD III COPD, 12% pulmonary arterial hypertension, 12% obstructive apnea-hypopnea syndrome, and 12% other conditions. ANOVA showed no difference between diagnostic categories for both test. Average score in 6MWT was 368.5 m and 1.01 m/s in 4MGST. Pearson correlation coefficient revealed significant positive correlation between results of both tests: high score in 4MGST is equivalent to high score in 6MWT. There was negative correlation with age and positive correlation with height. At one year follow-up, 16 patients had died. They obtained significantly lower scores in both tests (4MGST: 0.69 m/s and 6MWT: 248.1 m) Survival chance fell to 20% for patients walking slower than 0.69 m/s. It is possible to replace TC6M with T4M in patients with different respiratory pathologies, we can predict death for any cause if a subject walked at < speed at 0.69 m/s. T4M is cheap and easy to perform in primary care, serving as a risk assessment to refer to a more complex center.