Examining the uptake, retention, and effectiveness of a national online type 2 diabetes self-management intervention in England (Healthy Living): a retrospective cohort study

<b>Background</b><br/>The prevalence of type 2 diabetes (T2DM) is increasing rapidly in the UK and worldwide and is linked to adverse outcomes including premature death. Previous studies have shown that developing self-management skills in this population can lead to health improvements. The National Health Service in England has implemented Healthy Living (HL), an online Diabetes Self-Management Education and Support (DSMES) intervention, offering information about T2DM and help with adopting healthy behaviours.<br/><br/><b>Aims </b><br/>To examine uptake and retention of people living with T2DM registered with HL and how its use is associated with changes in 1-year clinical outcomes (effectiveness) compared with people with T2DM who did not register (controls). <br/><br/><b>Methods</b><br/>Anonymised linked patient-level HL and National Diabetes Audit (NDA) data were used to identify adults with T2DM in England. Multivariable logistic regression models identified predictors of participation in HL (uptake). Using 1-to-5 case-control propensity score matching (on age, sex, baseline HbA1c, body mass index (BMI), blood pressure (BP), cholesterol, ethnicity, deprivation) and multivariable linear/logistic models, we examined how HL use was related to 1-year HbA1c, BMI, BP, new insulin use, and completion of eight care processes recommended for people with diabetes (effectiveness). Several sensitivity/sub-group analyses assessed the robustness of findings.<br/><br/><b>Results</b><br/>A total of 21,820 people with T2DM activated a HL account. Compared with non-participants, account activators (cases) were more likely to be female (OR: 1.91; 95%CI: 1.85, 1.96), less likely to be Asian (OR: 0.35; 95% CI: 0.33, 0.37) or Black (OR: 0.56; 95% CI: 0.52, 0.60) compared with white people. Assessing effectiveness, 4,940 HL cases were matched to 24,685 NDA controls. Compared with controls, at 1-year, HL cases had lower HbA1c (by -1.3 mmol/mol (95% CI: -1.7, -0.8) or -0.1% (95% CI: -0.2, -0.1)); BMI (-0.2 kg/m2; 95% CI: -0.3, -0.1), systolic BP (-1.2 mmHg; 95% CI: -1.6, -0.7), and diastolic BP (-0.6 mmHg; 95% CI: -0.9, -0.3); higher odds of completing care processes (OR: 1.6; 95% CI: 1.5, 1.8), but non-significant for insulin use (OR: 1.0; 95% CI: 0.8, 1.2). Sensitivity/sub-group analyses were consistent with the main findings.<br/><br/><b>Conclusions </b><br/>People who activated a Healthy Living account experienced, on average, moderate health benefits compared with non-participants. These benefits would be expected to reduce risks for diabetes-related complications at a population level.<br/>