Evaluating the Short-Term Costs and Benefits of a Nationwide Diabetes Prevention Programme in England: Retrospective Observational Study

Evaluating the Long-Term Cost-Effectiveness of the English NHS Diabetes Prevention Programme using a Markov Model

BACKGROUND

In 2016, England launched the largest nationwide diabetes mellitus prevention programme, the NHS Diabetes Prevention Programme (NHS DPP). This paper seeks to evaluate the long-term cost-effectiveness of this programme.

METHODS

A Markov cohort state transition model was developed with a 35-year time horizon and yearly cycles to compare referral to the NHS DPP to usual care for individuals with non-diabetic hyperglycaemia. The modelled cohort of individuals mirrored the age profile of referrals received by the programme by April 2020. A health system perspective was taken, with costs in UK £ Sterling (price year 2020) and outcomes in terms of quality-adjusted life-years (QALYs). Probabilistic analysis with 10,000 Monte Carlo simulations was used. Several sensitivity analyses were conducted to explore the uncertainty surrounding the base case results, particularly varying the length of time for which the effectiveness of the programme was expected to last.

RESULTS

In the base case, using only the observed effectiveness of the NHS DPP at 3 years, it was found that the programme is likely to dominate usual care, by generating on average 40.8 incremental QALYs whilst saving £135,755 in costs for a cohort of 1000. At a willingness to pay of £20,000 per QALY, 98.1% of simulations were on or under the willingness-to-pay threshold. Scaling this up to the number of referrals actually received by the NHS DPP prior to April 2020, cost savings of £71.4 million were estimated over the 35-year time horizon and an additional 21,472 QALYs generated. These results are robust to several sensitivity analyses.

CONCLUSION

The NHS DPP is likely to be cost-effective. Indeed, in the majority of the simulations, the NHS DPP was cost-saving and generated greater QALYs, dominating usual care. This research should serve as evidence to support the continued investment or recommissioning of diabetes prevention programmes.

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.

Diabetes prevention at scale: Narrative review of findings and lessons from the DIPLOMA evaluation of the NHS Diabetes Prevention Programme in England

AIMS

The NHS Diabetes Prevention Programme (NHS DPP) is a large-scale, England-wide behaviour change programme for people at high risk of progressing to type 2 diabetes. We summarise the findings of our six-year DIPLOMA evaluation of its implementation and impact and highlight insights for future programmes.

METHODS

Using qualitative interviews, document analysis, observation, surveys and large dataset analysis, eight interlinked work packages considered: equity of access; implementation; service delivery and fidelity; programme outcomes; comparative effectiveness and cost-effectiveness in reducing diabetes incidence; and patient decision making and experience.

RESULTS

Delivery of the NHS DPP encountered barriers across many aspects of the programme, and we identified inequalities in terms of the areas, organisations and patient populations most likely to engage with the programme. There was some loss of fidelity at all stages from commissioning to participant understanding. Despite these challenges, there was evidence of significant reductions in diabetes incidence at individual and population levels. The programme was cost-effective even within a short time period.

CONCLUSIONS

Despite the challenge of translating research evidence into routine NHS delivery at scale, our findings suggest that an individual-level approach to the prevention of type 2 diabetes in a 'high-risk' population was more effective than usual care. By embedding evaluation with programme delivery and working closely with the NHS DPP team, we provided actionable insights for improving communications with potential participants, supporting primary care referral, honing the delivery model with better provider relationships and more patient choice, increasing understanding of behaviour change techniques, and enriching the educational and health coaching content.