A previous study examined patterns of diabetes medication use during the insulin transition among participants in a large clinical trial.[12] This study found that within the first year of insulin initiation, metformin was continued among most patients (80.3%), and the majority of patients continued taking -combinations of two or more diabetes medications along with insulin.[13] This study was limited in that medication use was only assessed at yearly intervals, creating a question about how and when such medication changes are occurring. This evidence concerns the gene INS and diabetes mellitus.