ICCs for the intercept-only model and adjusted model for the change, end and MCID scores for each measure of the total population in practices that provided ≥10 patients

Intercept-only modelAdjusted model
6MWT end score0.080.17#
6MWT change score0.000.01#
6MWT MCID improvement0.030.04#
6MWT MCID deterioration0.060.06
CCQ end score0.110.20#
CCQ change score0.060.09#
CCQ MCID improvement+0.050.07#
CCQ MCID deterioration+0.030.05#
GPE-DV end score0.140.15#
MRC end score0.080.12#
MRC change score0.230.34#

6MWT: 6-min walk test; CCQ: Clinical COPD Questionnaire; GPE-DV: Global Perceived Effect – Dutch Version; HHD: hand-held dynamometer; ICC: intraclass correlation coefficient; MCID: minimal clinically important difference; MRC: Medical Research Council Dyspnoea Scale; N.A: not applicable. #Increase in the ICC compared with the intercept-only model following the adjustment for the case-mix variables age, gender and baseline score of the measure. For the multilevel analysis of the 6MWT, we used an MCID of ± ≥30 m [33]. +For the multilevel analysis of the CCQ, we used an MCID of ± ≥0.4 points [34].