Current data confirm that the 6MWT , ISWT and ESWT are valid , reliable and responsive to change with some interventions .
However , results are sensitive to small changes in methodology .
Field walking tests are commonly employed to evaluate exercise capacity , assess prognosis and evaluate treatment response in chronic respiratory diseases .
In recent years , there has been a wealth of new literature pertinent to the conduct of the 6-min walk test ( 6MWT ) , and a growing evidence base describing the incremental and endurance shuttle walk tests ( ISWT and ESWT , respectively ) .
The aim of this document is to describe the st and ard operating procedures for the 6MWT , ISWT and ESWT , which can be consistently employed by clinicians and research ers .
6-minute walk work for assessment of functional capacity in patients with COPD.
UNLABELLED The 6-min walk ( 6MW ) test is commonly used to assess exercise capacity in patients with COPD and to track functional change result ing from disease progression or therapeutic intervention . Not surprisingly , distance covered has been the preferred outcome for this test . However , distance walked does not account for differences in body weight that are known to influence exercise capacity . OBJECTIVE The aim of this study was to evaluate the  6-min distance x body weight product ( 6MWORK ) as an improved outcome measure with a solid physiologic foundation . PATIENTS AND METHODS One hundred twenty-four men and women with moderate-to-severe COPD volunteered and completed the testing sequence , which included pulmonary function , a peak effort ramp cardiopulmonary exercise study with gas exchange , and the 6MW . Means and SD were generated for the variables of interest . Differences were analyzed using analysis of variance techniques . Correlation coefficients and receiver operating characteristic ( ROC ) curves were calculated for the 6-min walk distance ( 6MWD ) and 6MWORK with indexes of pulmonary function , work performance , and Borg scores for dyspnea and effort . RESULTS Men and women presented with a significant smoking history that also differed by gender ( 48 vs 66 pack-years , respectively ; p < 0.01 ) . The mean ( + /- SD ) FEV(1 ) values were 45 + /- 12.6 % and 48 + /- 12.1 % , respectively ( not significant ) , while the diffusing capacity of the lung for carbon monoxide ( DLCO ) was 14.7 + /- 6.1 vs 10.3 + /- 3.9 mL/min/mm Hg , respectively ( p < 0.001 ) , for men and women . The 6MWD averaged 416.8 + /- 79.0 m for men and 367.8 + /- 78.6 m for women , and these differences were significant ( p < 0.002 ) . When 6MWD was compared as the percent predicted of normal values , each gender presented with a similar reduction of 78.6 + /- 14.5 % vs 79.9 + /- 17.5 % ( p > 0.05 ) , respectively . 6MWORK averaged 35,370 + /- 9,482 kg/m and 25,643 + /- 9,080 kg/m ( p < 0.0001 ) for men and women , respectively . 6MWORK yielded higher correlation coefficients than did 6MWD when correlated with DLCO , lung diffusion for alveolar ventilation , FEV(1 ) , FEV(1)/FVC ratio , watts , peak oxygen uptake , peak minute ventilation , and peak tidal volume . The ROC curve demonstrated that 6MWORK had a significantly larger calculated area under the curve ( p < 0.05 ) [ plot of 100-sensitivity to specificity for each variable of interest for all subjects ] than 6MWD when differentiating an objective ly selected definition of low work capacity vs high work capacity ( bike ergometry work , < 55 vs > 55 W , respectively ) . CONCLUSIONS We conclude that work calculated as the product of distance x body weight is an improved outcome measure for the 6MW . 6MWORK can be used whenever the 6MW is required to estimate a patient 's functional capacity . This measure is also a common measure , which can be converted to indexes of caloric expenditure for direct cross-modality comparisons
Current data confirm that the 6MWT , ISWT and ESWT are valid , reliable and responsive to change with some interventions .
However , results are sensitive to small changes in methodology .
Field walking tests are commonly employed to evaluate exercise capacity , assess prognosis and evaluate treatment response in chronic respiratory diseases .
In recent years , there has been a wealth of new literature pertinent to the conduct of the 6-min walk test ( 6MWT ) , and a growing evidence base describing the incremental and endurance shuttle walk tests ( ISWT and ESWT , respectively ) .
The aim of this document is to describe the st and ard operating procedures for the 6MWT , ISWT and ESWT , which can be consistently employed by clinicians and research ers .