Level of attendance at the English National Health Service Diabetes Prevention Programme and risk of progression to type 2 diabetes

Background We evaluated the dose–response relationship between the level of attendance at the English National Health Service Diabetes Prevention Programme (DPP) and risk of progression to type 2 diabetes amongst individuals participating in the programme. Methods We linked data on DPP attendance for 51,803 individuals that were referred to the programme between 1st June 2016 and 31st March 2018 and attended at least one programme session, with primary care records of type 2 diabetes diagnoses from the National Diabetes Audit up to 31st March 2020. Weibull survival regressions were used to estimate the association between the number of programme sessions attended and risk of progression to type 2 diabetes. Results Risk of developing type 2 diabetes declined significantly for individuals attending seven of the 13 programme sessions and continued to decline further up to 12 sessions. Attending the full 13 sessions was associated with a 45.5% lower risk (HR: 0.545 95% CI: 0.455 to 0.652). Compared to individuals that only partially attended the programme, attendance at 60% or more of the sessions was associated with a 30.7% lower risk of type 2 diabetes (HR: 0.693 95% CI: 0.645 to 0.745). Conclusions Reducing the risk of progression to type 2 diabetes through diabetes prevention programmes requires a minimum attendance level at seven of the 13 programme sessions (54%). Retaining participants beyond this minimum level yields further benefits in diabetes risk reduction. Commissioners may wish to consider altering provider payment schedules to incentivise higher retention levels beyond 60% of programme sessions.