The 6-min walk test as a primary end-point in interstitial lung disease

Abstract

There is a need for clinical trial end-points to better assess how patients feel and function, so that interventions can be developed which alleviate symptoms and improve quality of life. Use of 6-min walk test (6MWT) outcomes as a primary end-point in interstitial lung disease (ILD) trials is growing, particularly for drugs targeting concurrent pulmonary hypertension. However, 6MWT outcomes may be influenced differentially by interstitial lung and pulmonary vascular components of ILD, making interpretation complicated. We propose that using 6MWT outcomes, including 6-min walk distance or oxygen desaturation, as primary end-points should depend upon the study population (how advanced the ILD is; whether vasculopathy is significant), the degree of disease progression, and, importantly, the effect of study treatment expected. We argue that the 6MWT as a single outcome measure is suitable as a primary end-point if the treatment goal is to improve functional performance or prevent disease progression within a study population of patients with advanced ILD or those with ILD and co-existent vasculopathy. In addition, we discuss the potential of composite primary end-points incorporating 6MWT outcomes, outlining important considerations to ensure that they are appropriate for the study population and treatment goals.

S1-Leitlinie Interdisziplinäre Diagnostik interstitieller Lungenerkrankungen im Erwachsenenalter

“…Er ist daher ein wichtiger funktioneller wie auch prognostischer Faktor, der bei ILD bei Erstdiagnostik und ggf. im Verlauf durchgeführt werden sollte [79]. In Abhängigkeit der körperlichen Leistungsfähigkeit und der spezifischen ILD-Diagnose kann eine Spiroergometrie sinnvoll sein (z.…”

Gait speed in idiopathic pulmonary fibrosis: Quickly stepping in the right direction

“…A myriad of pulmonary and systemic factors can result in exercise intolerance in patients with chronic respiratory disease. Different functional exercise tests with varying complexity and test requirements have been developed to objectively measure functional exercise capacity, providing opportunity for a more global assessment of health status that goes beyond lung function impairment 1 . Among these, the 6‐minute walk test (6MWT) is most widely used in patients with interstitial lung disease (ILD), including idiopathic pulmonary fibrosis (IPF).…”

“…Among these, the 6‐minute walk test (6MWT) is most widely used in patients with interstitial lung disease (ILD), including idiopathic pulmonary fibrosis (IPF). In patients with fibrotic ILD, 6‐minute walk distance (6MWD) is correlated with other important clinical markers (e.g., lung function, health‐related quality of life) and predicts mortality 1 . However, despite its widespread use, the 6MWT has several limitations and alternative objective measures may provide advantages.…”

“…Different functional exercise tests with varying complexity and test requirements have been developed to objectively measure functional exercise capacity, providing opportunity for a more global assessment of health status that goes beyond lung function impairment. 1 Among these, the 6-minute walk test (6MWT) is most widely used in patients with interstitial lung disease (ILD), including idiopathic pulmonary fibrosis (IPF). In patients with fibrotic ILD, 6-minute walk distance (6MWD) is correlated with other important clinical markers (e.g., lung function, healthrelated quality of life) and predicts mortality.…”

“…In patients with fibrotic ILD, 6-minute walk distance (6MWD) is correlated with other important clinical markers (e.g., lung function, healthrelated quality of life) and predicts mortality. 1 However, despite its widespread use, the 6MWT has several limitations and alternative objective measures may provide advantages.…”