Good repeatability ( for the 6MWT and ESWT ) and reproducibility ( for the 6MWT , 12-minute walk test , ISWT , ESWT , and incremental cycle ergometer test ) were reported by most studies assessing these tests , providing patients were familiarized with them beforeh and .
The 6MWT , ISWT , and particularly the ESWT were reported to be sensitive to therapeutic intervention .
Exercise tests are often used to evaluate the functional status of patients with COPD .
However , to the best of our knowledge , a comprehensive systematic comparison of these tests has not been performed .
We systematic ally review ed studies reporting the repeatability and /or reproducibility of these tests , and studies comparing their sensitivity to therapeutic intervention .
A factor analysis of dyspnea ratings, respiratory muscle strength, and lung function in patients with chronic obstructive pulmonary disease.
The purpose of this study was to demonstrate that clinical ratings of dyspnea and physiologic function are separate dimensions underlying the pathophysiology of chronic obstructive pulmonary disease ( COPD ) . We used principal-components factor analysis to confirm these dimensions using data collected prospect ively in 86 symptomatic patients with COPD . Three different instruments were used to rate dyspnea : a modified Medical Research Council ( MRC ) scale , the oxygen cost diagram ( OCD ) , and the baseline dyspnea index ( BDI ) . Measures of physiologic function included st and ard spirometric measures ( forced vital capacity [ FVC ] and forced expiratory volume in one second [ FEV1 ] ) and maximal inspiratory ( PImax ) and expiratory ( PEmax ) mouth pressures .  Age of the 65 male and 21 female subjects was 62.9 + /- 1.2 yr ( mean + /- SEM ) . All three clinical scales were significantly correlated with physiologic function ( range of r values , 0.32 to 0.45 ; p less than 0.05 ) , except for the relationship between the MRC scale and PEmax ( r = -0.14 ; p = NS ) . The factor analysis yielded three factors that accounted for 71.9 % of the total variance of the data : clinical ratings of dyspnea ( MRC scale , OCD , and BDI ) loaded on the first factor ; maximal respiratory pressures and gender loaded on the second factor ; and lung function and age loaded on the third factor . Additional post hoc factor analysis provided similar results when the sample was divided into two subgroups by r and omization , by severity of dyspnea ratings , or by severity of airflow obstruction . We conclude that dyspnea ratings , maximal respiratory pressures , and lung function are separate factors or quantities that independently characterize the condition of patients with COPD . ( ABSTRACT TRUNCATED AT 250 WORDS
Good repeatability ( for the 6MWT and ESWT ) and reproducibility ( for the 6MWT , 12-minute walk test , ISWT , ESWT , and incremental cycle ergometer test ) were reported by most studies assessing these tests , providing patients were familiarized with them beforeh and .
The 6MWT , ISWT , and particularly the ESWT were reported to be sensitive to therapeutic intervention .
Exercise tests are often used to evaluate the functional status of patients with COPD .
However , to the best of our knowledge , a comprehensive systematic comparison of these tests has not been performed .
We systematic ally review ed studies reporting the repeatability and /or reproducibility of these tests , and studies comparing their sensitivity to therapeutic intervention .