Correlation of Two-Minute and Six-Minute Walk Tests With Spirometric Indices in Patients With Severe Chronic Obstructive Pulmonary Disease at a Selected Tertiary Care Hospital in Puducherry

Background Chronic obstructive pulmonary disease (COPD) is a progressive respiratory condition characterised by airflow limitation and reduced exercise capacity. The Six-Minute Walk Test (6MWT) and Two-Minute Walk Test (2MWT) are commonly used to assess functional exercise capacity in COPD patients. This study aims to evaluate the correlation between the distance covered in the 2MWT and 6MWT with spirometric indices (such as Forced Expiratory Volume in 1 second (FEV₁), Forced Vital Capacity (FVC), and FEV₁/FVC) in COPD patients. Materials and methods This cross-sectional study involved 50 severe and very severe COPD patients diagnosed according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. Systematic random sampling was adopted to select the study participants. Each patient underwent spirometry to measure FEV₁, FVC, and FEV₁/FVC ratio. Following spirometry, both the 2MWT and 6MWT were conducted on separate days under standardised conditions. Results The average distance covered by the patients with very severe obstruction in 6MWT and 2MWT was 148±5.0 and 113.60±4.4. Patients with severe obstruction in 6MWT and 2MWT covered an average distance of 163.10±12.4 and 125.73±11.8, respectively. The mean FEV₁/FVC ratio and the mean FEV₁ % in 6MWT were 38.4 and 30.6 with a significant p-value of <0.001. The mean FEV₁/FVC ratio and the mean FEV₁ % in 2MWT were 32 and 29, respectively, with a significant p-value of <0.003. Both 2MWT and 6MWT distances were significantly correlated with spirometric indices, particularly FEV₁ and FEV₁/FVC ratio. Conclusion We found that there was no significant difference among spirometric indices between the two groups. Hence, 2MWT can be used as a reliable prognostic screening tool as it poses an advantage like decreasing the exhaustion for COPD patients as they find it more difficult to complete the 6MWT, resulting in increased heart rate and easy fatiguability.