Assessment of the value of 6-min walk test to predict the severity of interstitial lung disease among Indian patients

• Published in: Journal of Association of Chest Physicians Vol. 12; no. 1; pp. 11 - 19
• Main Authors: Sompalli, Anantha, Kailasa, Sateesh, Pulugundla, Varun, Kotha, Naveen Chandra, Sharma, Pawan, Velisela, Gopala, Ansari, Mohammed Soheb
• Format: Journal Article
• Language: English
• Published: Medknow Publications and Media Pvt. Ltd 01.01.2024; Wolters Kluwer Medknow Publications
• Subjects: 6-min distance walk test; 6-min walk test; CT imaging; hrct; india; interstitial lung disease (ild); Lung diseases; Medical research; Medicine, Experimental; spo2; India
• ISSN: 2320-8775; 2320-9089
• DOI: 10.4103/jacp.jacp_54_23

Introduction: The prevalence of interstitial lung disease (ILD) is increasing. High-resolution computerized tomography (HRCT), despite having limitations, remains the choice of method for diagnosis and assessment of severity of ILD. Objective: To determine the efficacy of 6-min walk test to assess the severity of the ILD compared to HRCT. Methodology: A cross-sectional study was done among 40 patients with ILD in a tertiary hospital in Hyderabad. The data included age, gender, smoking, HRCT, 6-min walk test, spirometry, diffusion lung capacity and medical history. Mann–Whitney U test, Kruskal–Wallis test, and ROC curve were used to determine the outcomes. Results: The mean age of participants was 57.18 + 13.01 years. 62.5% never smoked. Overall, 50% had severe ILD, and the rest had mild to moderate. The distance walked per 6-min, SpO 2 before and SpO 2 after, was significantly lower ( p = 0.001; 0.002; <0.001, respectively) among patients with severe ILD than mild or moderate. The sensitivity and 1-specificity of the distance walked in 6-min to detect the severity of ILD was 0.90 and 0.31, respectively; sensitivity and 1-specificity of SpO 2 before the test was 0.81 and 0.34, while that of SpO 2 after the test was 0.90 and 0.17, respectively. Conclusion: This study found that the 6-min walk test is highly sensitive and specific for predicting the severity of ILD among patients. All three components of the 6-min walk test: distance, oxygen saturation before, and oxygen saturation after the test significantly lowered and were independent predictors of severe ILD.