Prevalence of overestimation or underestimation of the functional capacity using MRC score as compared to 6-minute walk test in patients with cardio-respiratory disorders. (1st September 2014)

• Record Type: Journal Article
• Authors: Callens, Etienne; Graba, Sémia; Essalhi, Mohamed; Gillet-Juvin, Karine; Chevalier-Bidaud, Brigitte; Chenu, Romain; Mahut, Bruno; Delclaux, Christophe
• Is Part Of: COPD. Volume 11:Number 5(2014:Oct.)
• Page Start: 496
• Page End: 502
• Publication Date: 2014-09-01
• Subjects: activity-related dyspnea -- chronic obstructive pulmonary disease -- diffuse parenchymal lung disease -- pulmonary vascular disease -- chronic heart failure; Lungs -- Diseases, Obstructive -- Periodicals; 616.24
• DOI: 10.3109/15412555.2014.898037
• Languages: English
• ISSNs: 1541-2555

Abstract

Abstract: Objectives: The first objective of our study was to assess whether patients diagnosed with cardio-respiratory disorders report overestimation or underestimation on recall (Medical Research Council (MRC) dyspnea scale) of their true functional capacity (walked distance during a 6-minute walk test (6MWT)). The second objective was to assess whether the measurement of breathlessness at the end of a 6MWT (Borg score) may help to identify dyspneic patients on recall. Methods: The 6MWTs of 746 patients aged from 40 to 80 years who were diagnosed with either chronic obstructive pulmonary disease (COPD, n = 355), diffuse parenchymal lung disease (n = 140), pulmonary vascular diseases (n = 188) or congestive heart failure (n = 63) were selected from a prospective Clinical Database Warehouse. Results: The percentage of patients who overestimated (MRC≤ 2 with distance < lower limit of normal (LLN), 61/746, 8%; 95% confidence interval (CI): 6 to 10%) or underestimated (MRC > 2 with distance ≥LLN, 121/746, 16%; 95%CI: 14 to 19%) on recall their capacity was elevated. The overestimation seemed related to self-limitation, while the underestimation seemed related to patients who "work through" their breathing discomfort. These two latter groups of patients were mainly diagnosed with COPD. A Borg dyspnea score >3 (upper limit of normal) at the end of the 6MWT had 84% specificity for the prediction of a MRC score >1. Conclusion: Almost one fourth of patients suffering from cardio-pulmonary disorders overestimate or underestimate on recall their true functional capacity. An elevated Borg dyspnea score at the end of the 6MWT has a good specificity to predict dyspnea on recall.