PT  - JOURNAL ARTICLE
AU  - Christian Osadnik
AU  - Christine McDonald
AU  - Anne Holland
TI  - Are two six-minute walk tests necessary during acute exacerbations of COPD?
DP  - 2014 Sep 01
TA  - European Respiratory Journal
PG  - P1292
VI  - 44
IP  - Suppl 58
4099  - http://erj.ersjournals.com/content/44/Suppl_58/P1292.short
4100  - http://erj.ersjournals.com/content/44/Suppl_58/P1292.full
SO  - Eur Respir J2014 Sep 01; 44
AB  - Background: The six-minute walk test (6MWT) is a valid, reliable and widely used measure of exercise tolerance in COPD. Repeat testing is recommended during stable disease, however its necessity during an acute exacerbation of COPD (AECOPD) is unclear.Aims and objectives: To investigate the repeatability of the 6MWT during AECOPD and explore characteristics of those who demonstrate learning effects.Methods: 17 participants (7 male, mean age 69 years, FEV1 42% pred) who presented to hospital with AECOPD were recruited. Two 6MWTs (T1, T2) were performed in accordance with ATS/ERS guidelines at hospital discharge. Distance walked (6MWD) at T1 and T2 were compared via Bland-Altman plots. Exploratory comparisons between &#039;responders&#039; (T2 - T1 ≥ 30m) and &#039;non-responders&#039; were performed via unpaired t-tests.Results: Mean 6MWD difference (T2 - T1) was -4.9m but limits of agreement were wide (-114 to 104m). Compared to &#039;non-responders&#039;, &#039;responders&#039; (n = 6) had a significantly lower smoking history 22.1 (14) vs 75.5 (48) pack years, p = 0.02; shorter length of stay 2.7 (0.7) vs 7.0 (4.6) days, p = 0.04; and a trend towards more rests 1.7 (1) vs 0.6 (0.9), p = 0.052.Conclusion: There is marked variability between two 6MWDs on the same day at the end of a hospital admission for AECOPD. A single 6MWD may not be a reliable measure of functional exercise tolerance immediately following a COPD exacerbation.