Predictors of insulin uptake among adults with type 2 diabetes in the Stepping Up Study

Aims: We aimed to investigate predictors of insulin uptake, and change in insulin appraisals, among adults with type 2 diabetes mellitus (T2DM) who participated in the Stepping Up trial. Methods: The Stepping Up model of care, supporting timely insulin initiation in primary care, was evaluated in a two-armed cluster-randomised controlled trial. Participants were 266 adults (mean +/- SD age 62 +/- 10 years; 39% women) with T2DM (median (IQR) duration 8.5 (5, 13) years) from 74 primary care practices (Stepping Up intervention: 57%, control 43%). At 12 months, 47% (n = 126) had commenced insulin. Controlling for randomisation, logistic regression was used to explore baseline predictors of insulin uptake, including: demographic and clinical characteristics, emotional wellbeing (depressive symptoms and diabetes-related distress), insulin treatment appraisals, and, 'willingness' to initiate insulin. Two-way analysis of variance examined effects of, and interaction between, randomisation and insulin uptake on 12-month change in insulin appraisals. Results: Participants using insulin at 12 months were more likely (all p < 0.05) than those with non-insulin-treated T2DM to report: lower socioeconomic status, higher baseline HbA1c (median difference: 0.3%; 3 mmol/mol), greater willingness to commence insulin (very willing: 27% vs 12%), and less negative and more positive insulin appraisals. All contributed significantly to the final model (chi(2)(8) = 92.1, p < 0.001) except insulin appraisals. Regardless of trial allocation, those initiating insulin reported significantly greater reductions in negative insulin appraisals. Conclusions: Controlling for randomisation, 12-month insulin use was predicted by higher baseline HbA1c and 'willingness' to use insulin if recommended. Negative insulin appraisals reduced following insulin initiation. (C) 2017 Elsevier B.V. All rights reserved.