Carryover and period effects
Carryover and period effects were checked prior to main analysis. In line with the Statistical Analysis Plan, we examined first order carryover effects (i.e. carryover from the preceding period only) using mixed effects models with drug, period, and a carryover variable (i.e. drug in previous period) as fixed effects, participant as a random effect, and HbA1c as the outcome. The carryover variable used the same coding as the drug variable, or a 0 if in the first period (adjustment for period removes this part of the carryover term in analysis). We adjusted for period in primary analysis by adding as a fixed effect variable in the mixed effects models.