All models included BP trial assignment, glucose trial assignment, and presence or absence of cardiovascular events at baseline.
Factors introduced at randomization included participation in the blood pressure or lipid trial, assignment to intensive blood pressure treatment, and assignment to fenofibrate treatment (15, 16).
The rate ratio for falling for intensive compared with standard glycemic control did not differ by subtrial (blood pressure trial or lipid trial) assignment or subtrial intervention.
All the predictor variables were allowed to vary with time except for age, gender, race/ethnicity, and intervention trial assignment group.
This model also contained terms representing the glycaemia control study arm plus terms accounting for the following stratifying variables: assignment to the blood pressure control trial or the lipid control trial; assignment to the intensive blood pressure intervention in the blood pressure control trial; and assignment to receive fibrate in the lipid control trial.
Following standard ACCORD procedures, all analyses adjusted for presence of cardiovascular disease at baseline, assignment to either the blood pressure trial or the lipid trial, assignment to the intensive blood pressure intervention in the blood pressure trial, and assignment to receive fibrate in the lipid trial.
Three sets of models were fit: model 1 includes variables used to stratify randomization (second trial assignment [blood pressure or lipid]: randomized group allocation within the blood pressure trial or lipid trial and history of clinical cardiovascular disease).
Differences in event rates between randomized groups were tested using proportional hazards regression analysis adjusting for the design factors of clinical center network, baseline history of CVD, and BP trial or lipid trial assignment.
Each set modeled the change in the HRQL measure, and each set included the following terms: glycemia intervention, secondary trial assignment, prior CVD at baseline, the baseline HRQL measure, time, and a time-by-glycemia interaction term.
The results from the prespecified analyses, adjusted only for trial assignment and stratification variables, did not vary substantially from the results from a fully adjusted model including a variety of baseline covariates.
