Sample size
For each hypothesis, to detect a difference of 0.35SDs (equivalent to a 3.0mmol/mol difference between the two strata on the two different therapies with 90% power, alpha 0.05, we required 172 participants in each stratum. To allow for the possibility of uneven numbers in each stratum (up to a 60%:40% split), the sample size was increased to 358. To allow for a withdrawal rate of 15% and exclusion from primary analysis due to discontinuing at least one study drug (estimated at 19%), the sample size was increased to 520.