Sample size calculation
RECRUITMENT
Mean reductions in HbA1c, between baseline and follow-up, were assumed to be 0 mmol/mol (0·0%) in the usual care group, and 4·8 mmol/mol (0·5%) in the intervention group [At the time of recruitment, the COVID-19 epidemic was unfolding with vaccines not yet available. Considering the uncertainties surrounding the epidemic, we decided to assess all potentially eligible participants. Subsequently we consecutively randomised the first 206 of those meeting the eligibility criteria.