AN EVALUATION OF SIX MINUTE WALK TEST IN IMPROVING EXERCISE TOLERANCE IN PATIENTS OF IDIOPATHIC PULMONARY FIBROSIS

Abstract

Introduction: The six minute walk test (6MWT) is a practical and reliable measure of exercise tolerance that is used to assess the functional status of patients with many cardiac and pulmonary diseases, including heart failure, pulmonary hypertension, and chronic obstructive pulmonary disease. There is paucity of data establishing effectiveness of six minute walk test in patients with Idiopathic pulmonary fibrosis in India. In the present study we evaluated the effectiveness of six minute walk test in improving exercise tolerance and quality of life in Idiopathic pulmonary fibrosis patients

Methods:  This was a Prospective study design .  Subjects were randomly selected  diagnosed as Idiopathic Pulmonary Fibrosis according to the American Thoracic Society Criteria, FVC greater than or equal to 55% of predicted, Diffusing capacity of carbon monoxide (DL_co) greater than or equal to 35% of predicted. The 6MWT was performed at the baseline and at 18 weeks intervals.

Results: Mean (± SD) age at the entry of the study was 59 (±13) years and 82% of the study subjects were male. The mean (±SD) value for 6MWD at baseline and at 18 weeks was 214 (± 89) m and 271 (± 84) respectively. There were significant variations between the study subjects in terms of dyspnoea, six minute walk distance and SGRQ scores. The 6MWT had good reliability in patients with Idiopathic pulmonary fibrosis. The intraclass Pearson’s correlation coefficient for six minute walk distance between baseline and at 18 weeks was 0.6125(P< 0.05). The patient experienced good sense of relief from the activities that required tolerance due to the improvement in six minute walk distance.

Conclusion: The six minute walk test is consistent, suitable measure of exercise tolerance in IPF patients. A MCID of 15 m is less but much appreciable since there are no related studies representing Indian patients. The six minute walk test is a clinically helpful measure of status of the disease and the mortality.

Key Word : 6MWT , Idiopathic Pulmonary Fibrosis , ATC Criteria, Borg Scale , SGRQ scores