Validity of the 6-Minute Walk Test in Patients with End-Stage Lung Diseases Wearing an Oronasal Surgical Mask in Times of the COVID-19 Pandemic

Respiration. 2021;100(7):594-599. doi: 10.1159/000515606. Epub 2021 Apr 20.


Background and objectives: The 6-minute walk test (6MWT), as a clinical assessment tool for functional exercise capacity, is an integral component of lung allocation scores (LASs). In times of the coronavirus disease (COVID-19) pandemic, patients underwent 6MWTs wearing a surgical mask in ambulatory care. We investigated the impact of wearing a mask on 6-minute walk distances (6MWDs).

Method: 6MWDs of 64 patients with end-stage lung diseases wearing an oronasal surgical mask were retrospectively compared to previously investigated 6MWDs of the same cohort, in a pre-COVID-19 pandemic era, without wearing a mask. Four patients were excluded due to a primary vascular disease, 29 patients due to clinically unstable pulmonary functions, and 1 patient due to a psychiatric disorder.

Results: The median age of the patients included was 55 (46-58) years; 15 (48%) were male. Ten (32.2%) were on the Eurotransplant lung transplant waiting list with a median LAS of 34.3 (31.9-36.2). Twenty (64.5%) patients had chronic obstructive pulmonary diseases, 7 (22.6%) had interstitial lung diseases, and 4 (12.9%) had other end-stage lung diseases. The mean 6MWD without versus with wearing a mask was 306.9 (101.9) versus 305.7 (103.8) m, with a mean difference of -1.19 m (95% confidence interval -13.4 to 11.03). The observed difference is statistically equivalent to zero (p < 0.001). No significant differences in 6MWDs were observed between the clinical groups.

Conclusion: Wearing an oronasal surgical mask did not affect the 6MWDs of patients with advanced lung diseases. Therefore, a masked 6MWT appears to provide a reliable examination of functional exercise capacity in this cohort.

Keywords: 6-minute walk test; Advanced pulmonary disease; COVID-19 pandemic; Lung transplantation.

MeSH terms

  • Blood Gas Analysis
  • COVID-19 / prevention & control*
  • Chronic Disease
  • Exercise Tolerance
  • Female
  • Forced Expiratory Volume
  • Humans
  • Lung Diseases / physiopathology
  • Lung Diseases / surgery
  • Lung Diseases, Interstitial / physiopathology*
  • Lung Diseases, Interstitial / surgery
  • Lung Transplantation
  • Male
  • Masks*
  • Middle Aged
  • Minimal Clinically Important Difference
  • Plethysmography, Whole Body
  • Pulmonary Disease, Chronic Obstructive / physiopathology*
  • Pulmonary Disease, Chronic Obstructive / surgery
  • Reproducibility of Results
  • Respiratory Insufficiency / physiopathology*
  • Respiratory Insufficiency / surgery
  • Retrospective Studies
  • SARS-CoV-2
  • Vital Capacity
  • Walk Test / methods*