In this study, the patients underwent a submaximal test i.e. the  6 min-walk test (6MWT) wearing a surgical mask in outpatient care during COVID-19 times and found that the use of masked 6MWT may serve as a valid clinical assessment tool of functional exercise capacity.

To study the impact of wearing a Oronasal Surgical mask on 6-min walk distances (6MWDs).

The 6MWDs of 64 patients with stage-4 lung diseases using an oronasal surgical mask were compared to earlier examined 6MWDs of the same group without a mask, before COVID-19. Twenty-nine patients were excluded because of clinically unstable pulmonary functions, 4 due to a vascular disease, and 1 due to a menal illness.

Mean age of the included patients was 55 years and 15 of them were males. Ten patients (32.2%) were on the Eurotransplant lung transplant wait list with a median lung allocation scores (LAS) of 34.3. Twenty (64.5%) patients had chronic inflammatory lung illness, 7 (22.6%) had interstitial lung illnesses, and 4 (12.9%) had other stage-4 lung diseases. Mean 6MWD with no mask as compared to with a mask was 306.9 (101.9) and 305.7 (103.8) m. 

The use of facial surgical mask did not affect the 6MWDs of patients with end stage lung diseases.