Barriers to initiation of insulin therapy in poorly controlled type 2 diabetes based on self-determination theory

Proper glycaemic control can slow progression of diabetes complications. One of the main causes of poor glycaemic control is delayed initiation of insulin therapy.

To explain the reasons for delayed insulin initiation based on a behavioural model using patients' innate psychological needs.

We enrolled 151 patients with type 2 diabetes who had indications for insulin therapy. Thirty general practitioners (GPs) were included as care providers. Patients were studied by questionnaires evaluating components of self determination theory, such as competency, relatedness and autonomy. We also evaluated patients' attitudes towards insulin therapy using the Insulin Treatment Appraisal Scale questionnaire. GPs' attitudes towards insulin therapy were assessed with a different questionnaire.

Competency of patients was scored as acceptable (14.44/20). Relatedness score was low at around 15.63/30. The findings suggested that the patients' intrinsic motivation was less than their extrinsic motivation (8.41/15 vs 15.03/20). The main barrier to insulin therapy on the patients' side was rejection of severity of illness (67.5%). According to GPs, low compliance (96.7%) was the main cause of delayed insulin prescription.

We observed that patients do not have a proper understanding about their illness. Due to the low score of relatedness as a representative of patients and care providers' relationship, we highlight the importance of educating both about insulin therapy and how they can have the most effective relationship in this process.