PMID- 29070945
OWN - NLM
STAT- MEDLINE
DCOM- 20180625
LR  - 20190116
IS  - 1178-2005 (Electronic)
IS  - 1176-9106 (Print)
IS  - 1176-9106 (Linking)
VI  - 12
DP  - 2017
TI  - Minimal important difference and responsiveness of 2-minute walk test performance 
      in people with COPD undergoing pulmonary rehabilitation.
PG  - 2849-2857
LID - 10.2147/COPD.S143179 [doi]
AB  - BACKGROUND AND OBJECTIVES: Field exercise tests (eg, 6-minute walk test [6MWT]) 
      are important measures of functional exercise capacity in people with COPD. 
      Shorter tests such as the 2-minute walk test (2MWT) may offer advantages in some 
      populations but lack information about responsiveness to change. This study 
      examined responsiveness, minimal important difference (MID), test-retest 
      reliability, and construct validity of the 2MWT in people with stable COPD 
      attending outpatient pulmonary rehabilitation (PR). METHODS: At pre-PR 
      assessment, study participants completed a 2MWT twice in addition to usual 
      measures (6MWT and Chronic Respiratory Questionnaire). At post-PR assessment 
      following a standard PR program, measures were repeated and global rating of 
      change scores obtained (patient and therapist). Pre-post program change scores 
      were examined for correlations with change in 2-minute walk distance (2MWD) and 
      used (where r>/=0.3) to estimate the MID through anchor-based methods. 
      Distribution-based estimates based on standard error of measurement were 
      examined. Test-retest reliability (intraclass correlation coefficient [ICC] and 
      Bland-Altman agreement) and validity (Pearson correlation with 6-minute walk 
      distance [6MWD]) were reported. RESULTS: Fifty-nine people (28 men) with stable 
      COPD, mean age 68 years (SD 10 years), and percentage predicted forced expiratory 
      volume in 1 second 48% (SD 20%) attended pre-PR assessment. Test-retest ICC for 
      same-session 2MWD was 0.985. A mean difference of 2.4 m (95% confidence interval 
      [CI] 0.7-4.0 m, P=0.006) occurred between the first and second trials. 2MWD and 
      6MWD were highly correlated (r=0.87, P<0.001). Forty-one participants completed 
      PR and were included in responsiveness and MID analysis. Mean 2MWD improved 
      significantly post-PR (8.8 m, 95% CI 3.6-14 m, P=0.001). The MID in 2MWD, 
      anchored against clinically meaningful change in 6MWD, was 5.5 m (area under 
      curve =0.81, P=0.001). Distribution-based methods estimated an MID of 4 m. 
      CONCLUSION: Change in 2MWD of at least 5.5 m following a PR program corresponded 
      to a clinically meaningful change. A practice test is recommended due to learning 
      effects.
FAU - Johnston, Kylie Nicole
AU  - Johnston KN
AD  - School of Health Sciences, Sansom Institute for Health Research, University of 
      South Australia, Adelaide, SA, Australia.
FAU - Potter, Adrian James
AU  - Potter AJ
AD  - School of Health Sciences, Sansom Institute for Health Research, University of 
      South Australia, Adelaide, SA, Australia.
FAU - Phillips, Anna Caroline
AU  - Phillips AC
AD  - School of Health Sciences, Sansom Institute for Health Research, University of 
      South Australia, Adelaide, SA, Australia.
LA  - eng
PT  - Journal Article
DEP - 20171009
PL  - New Zealand
TA  - Int J Chron Obstruct Pulmon Dis
JT  - International journal of chronic obstructive pulmonary disease
JID - 101273481
SB  - IM
MH  - Aged
MH  - Ambulatory Care
MH  - *Exercise Tolerance
MH  - Female
MH  - Humans
MH  - Lung/*physiopathology
MH  - Male
MH  - Middle Aged
MH  - *Minimal Clinically Important Difference
MH  - Predictive Value of Tests
MH  - Psychometrics
MH  - Pulmonary Disease, Chronic Obstructive/*diagnosis/physiopathology/*rehabilitation
MH  - Recovery of Function
MH  - Reproducibility of Results
MH  - *Surveys and Questionnaires
MH  - Time Factors
MH  - Treatment Outcome
MH  - *Walk Test
PMC - PMC5640407
OTO - NOTNLM
OT  - COPD
OT  - exercise test
OT  - psychometrics
OT  - rehabilitation
COIS- Disclosure The authors report no conflicts of interest in this work.
EDAT- 2017/10/27 06:00
MHDA- 2018/06/26 06:00
PMCR- 2017/10/09
CRDT- 2017/10/27 06:00
PHST- 2017/10/27 06:00 [entrez]
PHST- 2017/10/27 06:00 [pubmed]
PHST- 2018/06/26 06:00 [medline]
PHST- 2017/10/09 00:00 [pmc-release]
AID - copd-12-2849 [pii]
AID - 10.2147/COPD.S143179 [doi]
PST - epublish
SO  - Int J Chron Obstruct Pulmon Dis. 2017 Oct 9;12:2849-2857. doi: 
      10.2147/COPD.S143179. eCollection 2017.