Overcoming clinical inertia in insulin initiation in primary care for patients with type 2 diabetes: 24-month follow-up of the Stepping Up trial
Diabetes is a prevalent condition, affecting 415 million adults globally. In Australia, over one million people have been diagnosed with type 2 diabetes (T2D). Effective management of T2D, including assisting people to achieve optimal glycaemia, is vital to reduce the development of complications and to contain costs. The majority of people with T2D will receive their care in general practice. Whilst rates of prescribing of insulin to people with T2D appear to be increasing in Australia, evidence suggests that the initiation of insulin therapy is often delayed in general practice.
The Stepping Up cluster randomised controlled trial tested a model of care for insulin initiation in general practice (practice training, clinical algorithms for insulin initiation and titration and diabetes educator (RN-CDE) support) compared to usual care. 266 participants from 74 general practices participated in the trial between 2012-2014; control practices received training in the model of care on completion of the 12-month trial. Patients were followed for an additional 12 months after trial completion. In this study we examined the two-year impact of the Stepping Up model of care intervention. Participant baseline characteristics, insulin and non-insulin medication use were summarised for each study group. Linear mixed-effects models with random intercepts were used to estimate differences in mean outcome (HbA1c and weight) between the study groups using restricted maximum likelihood estimation.
At baseline 61% of patients were male, mean (SD) age 62 (10) years, median (IQR) diabetes duration 9 (5, 13) years and mean (95% CI) HbA1c was 8.9 (8.8 to 9.1)% for both groups. The significant between group difference in HbA1c at 6 months was sustained at 24 months; Mean (95% CI) HbA1c at 24 months in the intervention group was 7.6 (7.5 to 7.8)% and 8.0 (7.7 to 8.4)% in the control group. At 24 months 97 (71.3%) of the intervention group and 26 (31.0%) of the control group were prescribed insulin; there was no significant difference in weight. Use of non-insulin anti-hyperglycaemic agents was similar in both groups with the exception of didpeptidyl peptidase-4 inhibitors which were prescribed more frequently in the control group (30(36%) vs 21(16%)).
Stepping Up was associated with improved glycaemic control compared to usual care sustained at 24 months, suggesting that the model facilitated more timely treatment intensification with sustained benefit. However, continued improvement was not observed after the first six months. Ongoing RN-CDE support and refreshment of the clinic staff in the model of care and current guidelines may facilitate ongoing treatment intensification. On the basis of these results an implementation study of Stepping Up, widened beyond insulin initiation to intensification of therapy generally, will be carried out in the North West Melbourne Primary Health Network.