Regarding the forced vital capacity (FVC) and percent predicted FVC (FVC%) secondary outcomes in our TRAIL1 study,1 we wish to clarify the perceived inconsistency between the statistical model results and the raw data summaries, particularly for usual interstitial pneumonia. Although outcomes were secondary and subgroup analyses were not pre-planned, the statistical model estimated larger declines in placebo compared with pirfenidone for FVC and FVC%, a pattern not visually apparent in the raw data plots.