INS and type 2 diabetes mellitus: In the Delay of Insulin Initiation in Patients with Type 2 Diabetes Mellitus Inadequately Controlled with Oral Hypoglycemic Agents [Analysis of Patient- and Physician-related Factors] (DIPP)-FACTOR study from Korea in 2017, the physician-related barriers included the physicians' concerns about the patients' refusal of treatment, patient compliance, hypoglycemia, lack of disease knowledge, and controllable disease with oral antidiabetic drugs (OADs) [15].