The Durability of an Intensive, Structured Education-Based Rehabilitation Protocol for Best Insulin Injection Practice: The ISTERP-2 Study

Introduction: Studies on the durability of an intensive, structured education protocol on best insulin injection practice are missing for people with type 2 diabetes mellitus (T2DM). The aim of this study was to assess the durability of an intensive, structured education-based rehabilitation protocol on best insulin injection practice in well-trained subjects from our previous intensive, multimedia intervention study registered as the ISTERP-1 study. A total of 158 subjects with T2DM from the well-trained group of the 6-month-long ISTERP-1 study, all of whom had successfully attained lower glucose levels compared to baseline levels with lower daily insulin doses and with less frequent and severe hypoglycemic episodes, participated in the present investigation involving an additional 6-month follow-up period, called the ISTERP-2 study. Methods: Participants were randomized into an intervention group and a control group, depending on whether they were provided or not provided with further education refresher courses for 6 months. At the end of the 6 months, the two groups were compared in terms of injection habits, daily insulin dose requirement, number of severe or symptomatic hypoglycemic events, and glycated hemoglobin (HbA1c) levels. Results: Despite being virtually superimposable at baseline, the two groups behaved quite differently during the follow-up. The within-group analysis of observed parameters showed that the subjects in the intervention group maintained and even improved the good behavioral results learned during the ISTERP-1 study by further reducing both the rate of injection technique errors (p < 0.001) and size of lipohypertrophic lesions at injection sites (p < 0.02). Conversely, those in the control group progressively abandoned best practice, except for the use of ice-cold insulin and, consequently, had significantly higher HbA1c levels and daily insulin dose requirements at the end of the follow-up than at baseline (p < 0.05). In addition, as expected from all the above, the rate of hypoglycemic episodes also decreased in the intervention group (p < 0.05), resulting in a significant difference between groups after 6 months (p < 0.02). Conclusion: Our data provide evidence that intensive, structured education refresher courses have no outstanding durability, so that repeated refresher courses, at least at 6-month intervals, are needed to have positive effects on people with T2DM, contributing not only to prevention but also to long-term rehabilitation. Trial Registration: Trial Registration no. 118 bis/15.04.2018.