Using 6-Min Walk Distance Expressed as a Percentage of Reference to Evaluate the Effect of Pulmonary Rehabilitation in Elderly Patients With Interstitial Lung Disease

Abstract

Purpose: The aim of this study was to investigate the effect of outpatient pulmonary rehabilitation (PR) program and the use of 6-min walk distance (6MWD), expressed as a percentage of the predicted value (%6MWD), to quantify response to PR in elderly patients with interstitial lung disease (ILD).

Methods: This was a prospective, nonrandomized controlled study. Forty eligible patients with stable ILD (≥65 y old) were advised to attend an outpatient PR program for 3 mo. Thirteen patients completed the PR program and formed the PR group. Ten patients who did not attend the PR program were evaluated after 3 mo and formed the control group. Patients in the PR group underwent a comprehensive 3-mo hospital-based outpatient PR program, consisting of educational support and supervised exercise training, and attended the rehabilitation unit weekly.

Results: Change in the absolute 6MWD (Δ6MWD) in the PR group was not significantly different compared with the control group (P = .062). Change in %6MWD (Δ%6MWD) was greater in the PR group than in the control group. Baseline 6MWD was not correlated with Δ6MWD, but baseline %6MWD was significantly correlated with Δ6MWD and Δ%6MWD.

Conclusion: PR had a beneficial effect on elderly patients with ILD in terms of exercise endurance. %6MWD might be more useful than the absolute 6MWD as an outcome measure of PR and as a predictor of response to PR in elderly patients with ILD.