Table 3.

Criteria to Establish Change in 6MWD as a Mediator in Relationship Between Treatment Assignment and Development of a Clinical Event at 12-Week Follow-Up

Criteria	Results*
Treatment assignment has a significant effect on Δ6MWD from baseline to 12-wk follow-up	Mean difference, 22.4 (95% CI, 15.9–28.9)
Δ6MWD has a significant effect on the odds of developing a clinical event	OR, 0.89 per 10 m (95% CI,0.87–0.91)
Treatment assignment has a significant effect on the odds of developing a clinical event at 12-wk follow-up	OR, 0.43 (95% CI, 0.31–0.59)
The effect of treatment assignment on the odds of developing a clinical event (compare with above) is attenuated with the addition of Δ6MWD to the model	OR, 0.52 (95% CI, 0.37–0.73)

6MWD indicates 6-minute walk distance; CI, confidence interval; and OR, odds ratio.

^*All models include adjustment for study and baseline walk; assignment to placebo is the reference for all models that included treatment.