The effectiveness of delivery modalities of non-pharmacological diabetes prevention programs: A systematic review and component network meta-analysis

Background and aims: Type 2 diabetes prevention programs are effective but costly and intensive, making translation into routine primary care and community settings challenging. Identifying drivers of intervention effectiveness can inform pragmatic future implementation whilst maintaining effectiveness. Translational studies have demonstrated that delivery modalities impact their effectiveness. This systematic review and component network meta-analysis assessed which delivery modality components of non-pharmacological diabetes prevention programs are associated with reductions in type 2 diabetes incidence for individuals at high risk of type 2 diabetes (or pre-diabetes). 

Methods: We searched MEDLINE, The Cochrane Library, Opengrey and clinicaltrials.gov from inception to November 17, 2022 for translational studies comparing lifestyle interventions with a minimum 12-month follow-up. Two investigators extracted the data. Random effects network meta-analyses and component network meta-analyses estimated the intervention effects. 

Results: We identified 50 eligible studies involving 29,286 participants including thirty-six (72.0 %) randomized controlled trials, 10 (20.0 %) cluster randomized controlled trials, and four (8.0 %) observational studies. Component network meta-analyses found in-person (individually) delivery was associated with greater reduction in incidence of type 2 diabetes (hazard ratio: 0.66, 95 % credible interval: 0.41, 0.96) and in-person (group-based) delivery was associated with greater reductions in weight (mean difference: −1.53 kg, 95 % credible interval: −2.18, −0.85) and HbA1c (mean difference: −0.74 mmol/mol, 95 % credible interval: −1.28, −0.17), relative to usual care. 

Conclusions: This analysis suggests in-person delivery modalities are most effective for diabetes prevention. Future research should focus on improving the effectiveness of digital programs and ensuring preferential delivery for target populations to reduce health inequalities.