Contact frequency determines outcome of basal insulin initiation trials in type 2 diabetes

Aims/hypothesis The aim of the present study was to investigate whether predetermined contact frequency with the study team and endpoint insulin dose are associated with study outcomes in basal insulin initiation trials in type 2 diabetes. Methods A systematic Medline search was performed. Using data from the selected studies, contact frequency was plotted against HbA₁c reduction and endpoint insulin dose. The importance of face-to-face vs telephone contact was also analysed. Insulin dose was plotted against HbA₁c reduction, hypoglycaemia rate and weight gain. To investigate non-specific study effects, the relationship between contact frequency and HbA₁c was also assessed in dipeptidyl peptidase-4 (DPP-4) inhibitor trials. Results The reduction in HbA₁c was highly correlated with contact frequency and endpoint insulin dose (r ² = 0.751, p