Health-Economic Modelling of Improved Behavior in Insulin Injection Technique in Belgium

Background: Adequate insulin injection technique (IIT) is crucial to optimize the efficacy of diabetes therapy. Widespread non-practice of injection-site rotation and frequent reuse of insulin pen needles (PN) promote high rates of lipohypertrophy (LH) among people living with diabetes (PwD). LH is associated with increased insulin requirement and suboptimal insulin absorption leading to worsened glycemic control and increased risk for hypoglycemia. Avoiding out-of-the-pocket patient costs of PN could reduce PN reuse, thereby limiting its contribution to LH occurrence. Objectives: A model was developed to compute the impact of a behavior shift in reuse on clinical and economic outcomes for type 1 and insulin-treated type 2 diabetes populations in Belgium. Methods: Patient populations were characterized by treatment-specific characteristics and grouped by their frequency of PN replacement. The intervention was modelled to cause a change in reuse frequency, with the effects propagating downstream of the model. Model and input parameters were based on literature research and expert opinions from a Delphi panel, since available data was found to be limited, incomplete or inconsistent and assumptions were needed. Results: Using the current situation as comparator, this analysis showed a reduction of healthcare expenditures following an improvement in IIT. Considering a 5-year time horizon, this study yields potential savings of 52.6 million euros (28.1–77.9 million euros) when 55% of PwD improve PN reuse behavior. Conclusion: Our model shows that even in an era of technological advances and established diabetes care, lack of adherence to correct IIT has an important impact on economic and health outcomes of PwD in Belgium.