Association Between Treatment Group and MCID Change Category
diabetes
REGRESSION, DIABETES
Given participants were nested within cohorts that were also nested within sites, we calculated intraclass correlation coefficients (ICC) for the total DDS-17 as well as the 4 subscales to determine whether multilevel models accounting for dependency in the data were warranted. The degree of variance in the DDS-17 attributable to differences between both cohort and site (ie, ICCs >0.05), indicated that multilevel models accounting for the dependency of participants (level 1) within cohorts (level 2) within sites (level 3) were warranted. For the DDS-17 and each of the 4 subscales, 2 sets of multilevel logistic regression models were used to evaluate differences between EPICC and EUC participants in DDS-17 MCID categories. The first set consisted of an examination of treatment group (in which EPICC = 1 and EUC = 0) as a factor of whether a participant showed MCID improvement (with yes = 1 and no = 0, which collapsed no change and worsening) and the second set consisted of an examination of treatment group as a factor of whether a participant showed MCID worsening (with 1 = yes and 0 = no, which collapsed no change and improvement). For each set, 5 models were conducted: 1 for DDS-17 and the 4 subscales. Prior diabetes education was included as a covariate in all models examining differences between treatment groups, given differences between treatment groups in this variable.