INS and type 2 diabetes mellitus: Notably, the tree analysis sheds light upon the interaction between those variables and thus defined the hierarchical impact of these variables on insulin treatment initiation, identifying T2DM patients on sulphonylurea, with high HbA1c, eGFR below 50 ml/min/1.73 m2, and at least 5 years of disease duration as those at very high risk to start insulin treatment.