PT  - JOURNAL ARTICLE
AU  - Steven Nathan
AU  - Carlo Albera
AU  - Roland du Bois
AU  - Williamson Bradford
AU  - Ulrich Costabel
AU  - Talmadge King
AU  - Paul Noble
AU  - Steven Sahn
AU  - Dominique Valeyre
TI  - 6-minute walk test (6MWT) in patients with idiopathic pulmonary fibrosis (IPF): Confirmation of the minimal clinically important difference (MCID)
DP  - 2012 Sep 01
TA  - European Respiratory Journal
PG  - P3656
VI  - 40
IP  - Suppl 56
4099  - http://erj.ersjournals.com/content/40/Suppl_56/P3656.short
4100  - http://erj.ersjournals.com/content/40/Suppl_56/P3656.full
SO  - Eur Respir J2012 Sep 01; 40
AB  - Introduction: The 6MWT is a practical measure of exercise tolerance in patients with IPF. MCID estimates for 6MWT distance (6MWD) in patients with IPF have ranged between 10–58 m [1-3]; we sought to confirm these estimates in an independent cohort of patients with IPF.Methods: All patients randomized to placebo in the CAPACITY studies were included in the analysis. Both distribution- and anchor-based methods were used to estimate the MCID for 6MWD. Distribution-based analyses included standard error of measurement (SEM) and effect size (ES); anchor-based analyses used criterion referencing to estimate the difference in 6MWD between those who did and did not experience significant health events.Results: A total of 345 patients were included in the analysis. The mean (SD) baseline 6MWD was 404.6 m (90.4). The estimated SEM for 6MWD was 37 m (95% CI, 34–40). The estimated ES was 0.32, based on a mean change of 29.2 m from baseline to Wk 48. 6MWD values were significantly different for those who experienced the composite endpoint of hospitalization or death vs. those who did not; the corresponding MCID was 21.7 m (p=0.047). Conclusions: Analysis of 6MWD data from a large cohort of IPF patients yielded an MCID estimate of 22–37 m. This finding is consistent with previous estimates which, taken together, provide a meaningful benchmark for assessing 6MWD in patients with IPF.