Table 1.

Key attributes and limitations of the 6-min walk test in patients with IPF

Attributes	Limitations
• Easy and inexpensive to perform	• Results affected by multiple factors  ○ Age/sex/weight/height  ○ Comorbidities that affect ability to walk or desaturation  ○ Use of supplemental oxygen  ○ Specific instructions given to patient, which may be affected by language barriers  ○ Training effects
• Reproducible
• Replicates activities of daily living
• Provides a functional measure of the patient’s overall cardiopulmonary reserve
• 6MWD correlates with measures of lung function and HRQL
• 6MWD, and particularly decline in 6MWD, are strong predictors of mortality
	• Provides no insight into mechanism/s of exercise limitation
	• Unclear which parameter measured during 6MWT is of greatest prognostic value
	• Use of different methodologies across studies hinders comparison of results

6MWD 6-min walk distance, 6MWT 6-min walk test, HRQL health-related quality of life