NHS Diabetes Prevention Programme Research Articles

Prediabetes, participation in the English National Health Service Diabetes Prevention Programme, and associations with COVID-19-related mortality: A whole population study

AimsTo assess the effects of non-diabetic hyperglycaemia (NDH, also known as pre-diabetes), including the impact of the NHS Diabetes Prevention Programme (NHS DPP), on COVID-19-related mortality during the pandemic. MethodsThis study included all 61,438,225 individuals registered with General Practices in England and alive on 1st March 2020. We assessed COVID-19-related mortality in the 2,290,280(3.7 %) individuals with diagnosed NDH between March 2020 and February 2022 compared to those without diagnosed NDH or diabetes using Cox regression to adjust for demographic factors and cardiovascular comorbidities. Individuals with diagnosed NDH were further sub-categorised based on their contact with the NHS DPP (N = 376,590). Analyses were stratified by age (years) (<50, 50–69 and ≥ 70). ResultsThere were 158,070 COVID-19 deaths; 17,280(11 %) for people with diagnosed NDH. The adjusted hazard ratio (HR) was 0.95(0.93–0.96),p < 0.001 for those with diagnosed NDH compared to those without diagnosed diabetes or NDH. By age (years), HRs were, 2.53(2.23–2.88),p < 0.001 for < 50, 1.29(1.24–1.35),p < 0.001 for 50–69 and 0.87(0.85–0.89),p < 0.001 for ≥ 70. NHS DPP attendance was associated with lower COVID-19 mortality with a dose–response relationship with engagement. ConclusionsYounger people with diagnosed NDH were at higher relative risk of COVID-19 mortality. Attendance at the NHS DPP was associated with significantly lower COVID-19-related mortality.

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

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. A Markov cohort state transition model was developed with a 35-year time horizon and yearly cycles to compare referral to the NHS DPPto 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. In the base case, using only the observed effectiveness of the NHS DPP at 3years, 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. 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.

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

The Diabetes Prevention Programme 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. 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. 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. Despite the challenge of translating research evidence into routine NHS delivery at scale, our findings suggest that an individual-level approach to 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.

Could diabetes prevention programmes result in the widening of sociodemographic inequalities in type 2 diabetes? Comparison of survey and administrative data for England

BackgroundThe NHS Diabetes Prevention Programme (DPP) in England is a behavioural intervention for preventing type 2 diabetes mellitus (T2DM) among people with non-diabetic hyperglycaemia (NDH). How this programme affects inequalities...

Study shows diabetes prevention programme reduced development of T2D by 20%

In England, the NHS Diabetes Prevention Programme is offered to adults with pre-diabetes, with lifestyle advice to help reduce the risk of developing type 2 diabetes. The programme is intended to reduce the yearly cost of type 2 diabetes to the NHS by £8.8 billion, which is almost 9% of its budget, according to Diabetes UK. People with pre-diabetes are particularly at high risk of developing type 2 diabetes mellitus. Researchers from the University of Manchester have therefore set out to investigate whether people who were referred to the programme were less likely to develop type 2 diabetes, compared with those who were not referred to the programme. To do this, the investigators used a cohort study of patients attending primary care in England using clinical Practice Research Datalink data from 1 April 2016 (NHS Diabetes Prevention Programme introduction) to 31 March 2020. Patients referred to the programme from referring practices were matched to patients in non-referring practices to minimize confounding. Patients were matched based on age, sex, and date of pre-diabetes diagnosis (within 365 days). Analysis was adjusted for age (at index date), sex, time from pre-diabetes diagnosis to index date, BMI, HbA1c, total serum cholesterol, systolic blood pressure, diastolic blood pressure, prescription of metformin, smoking status, socioeconomic status, a diagnosis of depression, and comorbidities. A total of 18 470 patients referred to the NHS Diabetes Prevention Programme were matched with 51 331 patients not referred to NHS Diabetes Prevention Programme in the main analysis. Mean follow-up from referral was 482.0 and 472.4 days, respectively. The researchers identified that the risk of developing type 2 diabetes was 20% lower in people with raised blood sugars referred to the programme, compared with people who were not referred and who received usual care. While caution is needed to fully interpret the findings of this observational study, findings from the study supported the overall effectiveness of the programme. In addition, it would support the decision of the ‘rapid large-scale implementation’ of the programme in England, rather than a slower or regional introduction, as well as the continuation of the programme and the introduction of similar programmes to the rest of the United Kingdom.

The influence of demographic, health and psychosocial factors on patient uptake of the English NHS diabetes prevention programme

BackgroundThe prevention of type 2 diabetes (T2DM) is a major concern for health services around the world. The English NHS Diabetes Prevention Programme (NHS-DPP) offers a group face-to-face behaviour change intervention, based around exercise and diet, to adults with non-diabetic hyperglycaemia (NDH), referred from primary care. Previous analysis of the first 100,000 referrals revealed just over half of those referred to the NHS-DPP took up a place. This study aimed to identify the demographic, health and psychosocial factors associated with NHS-DPP uptake to help inform the development of interventions to improve uptake and address inequities between population groups.MethodsDrawing on the Behavioral Model of Health Services Utilization we developed a survey questionnaire to collect data on a wide range of demographic, health and psychosocial factors that might influence uptake of the NHS-DPP. We distributed this questionnaire to a cross-sectional random sample of 597 patients referred to the NHS-DPP across 17 general practices, chosen for variation. Multivariable regression analysis was used to identify factors associated with NHS-DPP uptake.Results325 out of 597 questionnaires were completed (54%). Only a third of responders took up the offer of a place. The best performing model for uptake (AUC = 0.78) consisted of four factors: older age; beliefs concerning personal vulnerability to T2DM; self-efficacy for reducing T2DM risk; and the efficacy of the NHS-DPP. After accounting for these, demographic and health-related factors played only a minor role.ConclusionUnlike fixed demographic characteristics, psychosocial perceptions may be amenable to change. NHS-DPP uptake rates may be improved by targeting the beliefs of patients about their risk of developing T2DM, their ability to carry out and sustain behaviours to reduce this risk, and the efficacy of the NHS-DPP in providing the necessary understanding and skills required. The recently introduced digital version of the NHS DPP could help address the even lower uptake amongst younger adults. Such changes could facilitate proportional access from across different demographic strata.

Unravelling the potential of social prescribing in individual-level type 2 diabetes prevention: a mixed-methods realist evaluation

BackgroundSocial prescribing (SP) usually involves linking patients in primary care with services provided by the voluntary and community sector. Preliminary evidence suggests that SP may offer a means of connecting patients with community-based health promotion activities, potentially contributing to the prevention of long-term conditions, such as type 2 diabetes (T2D).MethodsUsing mixed-methods realist evaluation, we explored the possible contribution of SP to individual-level prevention of T2D in a multi-ethnic, socio-economically deprived population in London, UK. We made comparisons with an existing prevention programme (NHS Diabetes Prevention Programme (NDPP)) where relevant and possible. Anonymised primary care electronic health record data of 447,360 people 18+ with an active GP registration between December 2016 and February 2022 were analysed using quantitative methods. Qualitative data (interviews with 11 primary care clinicians, 11 social prescribers, 13 community organisations and 8 SP users at high risk of T2D; 36 hours of ethnographic observations of SP and NDPP sessions; and relevant documents) were analysed thematically. Data were integrated using visual means and realist methods.ResultsPeople at high risk of T2D were four times more likely to be referred into SP than the eligible general population (RR 4.31 (95% CI 4.17–4.46)), with adjustment for socio-demographic variables resulting in attenuation (RR 1.33 (95% CI 1.27–1.39)). More people at risk of T2D were referred to SP than to NDPP, which could be explained by the broad referral criteria for SP and highly supportive (proactive, welcoming) environments. Holistic and sustained SP allowed acknowledgement of patients’ wider socio-economic constraints and provision of long-term personalised care. The fact that SP was embedded within the local community and primary care infrastructure facilitated the timely exchange of information and cross-referrals across providers, resulting in enhanced service responsiveness.ConclusionsOur study suggests that SP may offer an opportunity for individual-level T2D prevention to shift away from standardised, targeted and short-term strategies to approaches that are increasingly personalised, inclusive and long-term. Primary care-based SP seems most ideally placed to deliver such approaches where practitioners, providers and commissioners work collectively to achieve holistic, accessible, sustained and integrated services.

Latest audit shows the Diabetes Prevention Programme is pressing ahead in tackling non‐diabetic hyperglycaemia and type 2 risk

Findings from the latest National Diabetes Audit of the NHS Diabetes Prevention Programme (DPP) may point the way forward in reducing the incidence of type 2 diabetes.As shown by the audit, inequity of outcomes and variations in care processes still prevail, along with the need to refer people with non‐diabetic hyperglycaemia to the DPP. The audit report's recommended measures to address these could be a promising route forward. Steve Chaplin reports.

Effectiveness of digital and remote provision of the Healthier You: NHS Diabetes Prevention Programme during the COVID-19 pandemic.

To assess weight change in the Healthier You: NHS Diabetes Prevention Programme (NHS DPP) delivered via video conferencing (remote) sessions or delivered via specific digital interventions through apps or websites, during the COVID-19 pandemic compared to group-based face-to-face interventions, pre-pandemic. Prospectively collected national service-level data relating to individuals with non-diabetic hyperglycaemia (HbA1c 42-47 mmol/mol (6.0%-6.4%) or fasting plasma glucose 5.5-6.9 mmol/L) referred to the NHS DPP from June 2016 to March 2022. Between March 2020 and March 2022, 335,961 people were referred to the programme and were offered a choice of remote or digital intervention. This was preceded by 556,793 people referred to the face-to-face programme between June 2016 and February 2022. Uptakes to intervention sessions were 47% for those offered a choice and 39% for face-to-face. Remote and digital participants were significantly younger (60 and 56 vs. 65 years) and heavier (86.1kg and 91.0kg vs. 84.1kg) compared to face-to-face. Weight change was assessed for 42,407 remote, 7699 digital and 97,205 face-to-face participants with sufficient time to have finished the programme and no missing data. Mean weight losses for participants attending at least one intervention session were: 2.40 (2.36-2.44) kg, 2.59 (2.49-2.68) kg and 2.01 (1.98-2.04) kg for remote, digital and face-to-face participants respectively. Corresponding mean weight losses for those who completed the programme were: 3.24 (3.19-3.30) kg, 4.76 (4.60-4.92) kg and 3.04 (3.00-3.07) kg. There were no significant differences in weight change between interventions by ethnicity and deprivation. Weight losses achieved through remote and digital interventions were greater than those previously achieved through face-to-face interventions, without evidence of exacerbation of health inequalities.

Attendance, Weight Loss, and Participation in a Behavioural Diabetes Prevention Programme

BackgroundWeight loss in diabetes prevention programmes has been shown to be associated with participants’ age, socio-economic status, and ethnicity. However, little is known about how these differences relate to attendance and whether such differences can be mediated by other potentially modifiable factors. Differential effectiveness across these factors may exacerbate health inequalities.MethodProspective analysis of participant data collected by one provider of the standardised national NHS diabetes prevention programme in England. Mediation analysis was performed via a structural equation model to examine whether the number of attended sessions mediated the associations of age, socio-economic status, and ethnicity with follow-up weight. The group-level factor of number of attended sessions was examined using multiple linear regression as a benchmark; multilevel linear regression using three levels (venue, coach, and group); and fixed effects regression to account for venue-specific and coach-specific characteristics.ResultsThe associations of age, socio-economic status, and ethnicity with follow-up weight were all mediated by the number of attended sessions. Group size was associated with attendance in an inverted ‘U’ shape, and the number of days between referral and group start was negatively associated with attendance. Time of day, day of the week, and the number of past groups led by the coach were not associated with attendance.ConclusionMost of the differences in weight loss initially attributed to socio-demographic factors are mediated by the attendance of the diabetes prevention programme. Therefore, targeted efforts to improve uptake and adherence to such programmes may help alleviate inequalities.

How a commissioning support unit increased primary care referrals from the Black Country Integrated Care System to the NHS Diabetes Prevention Programme

How a commissioning support unit increased primary care referrals from the Black Country Integrated Care System to the NHS Diabetes Prevention Programme

Does recruiting patients to diabetes prevention programmes via primary care reinforce existing inequalities in care provision between general practices? A retrospective observational study

BackgroundPrimary care plays a crucial role in identifying patients’ needs and referring at-risk individuals to preventive services. However, well-established variations in care delivery may be replicated in this prevention activity.ObjectiveTo...

Population level impact of the NHS Diabetes Prevention Programme on incidence of type 2 diabetes in England: An observational study.

SummaryBackgroundThe NHS Diabetes Prevention Programme (DPP) is the first nationwide type 2 diabetes prevention programme targeting people with prediabetes. It was rolled out across England from 2016 in three waves. We evaluate the population level impact of the NHS DPP on incidence rates of type 2 diabetes.MethodsWe use data from the National Diabetes Audit, which records all individuals across England who have been diagnosed with type 2 diabetes by 2019. We use difference-in-differences regression models to estimate the impact of the phased introduction of the DPP on type 2 diabetes incidence. We compare patients registered with the 3,282 general practices enrolled from 2016 (wave 1) and the 1,610 practices enrolled from 2017 (wave 2) to those registered with the 1,584 practices enrolled from 2018 (final wave).FindingsIncidence rates of type 2 diabetes in wave 1 practices in 2018 and 2019 were significantly lower than would have been expected in the absence of the DPP (difference-in-differences Incident Rate Ratio (IRR) = 0·938 (95% CI 0·905 to 0·972)). Incidence rates were also significantly lower than expected for wave 2 practices in 2019 (difference-in-differences IRR = 0·927 (95% CI 0·885 to 0·972)). These results remained consistent across several robustness checks.InterpretationIntroduction of the NHS DPP reduced population incidence of type 2 diabetes. Longer follow-up is required to explore whether these effects are maintained or if diabetes onset is delayed.FundingThis research was funded by the National Institute for Health and Care Research (Health Services and Delivery Research, 16/48/07 – Evaluating the NHS Diabetes Prevention Programme (NHS DPP): the DIPLOMA research programme (Diabetes Prevention – Long Term Multimethod Assessment)). The views and opinions expressed in this manuscript are those of the authors and do not necessarily reflect those of the NHS, the National Institute for Health and Care Research or the Department of Health and Social Care.

Influences of decisions to attend a national diabetes prevention programme from people living in a socioeconomically deprived area.

AimsTo explore key influences of decisions in participants from a socioeconomically deprived area to attend the Healthier You: NHS Diabetes Prevention Programme (NHSDPP). The NHSDPP is a lifestyle behaviour change programme for adults with prediabetes living in England.MethodsSemi‐structured interviews were conducted with 35 participants who had attended the initial assessment, but not yet started the NHSDPP; 23 were classified as “attenders,” 12 as “non‐attenders” after they were interviewed based on whether they had attended the first NHSDPP session or not. Transcribed interviews were analysed using inductive thematic analysis.ResultsSeven themes were derived from the data. The results demonstrate how understanding type 2 diabetes, making lifestyle changes, comparing themselves with others, having support and certain self‐perceptions can all affect individuals’ motivation to attend a diabetes prevention programme. Accessibility and practicalities also influenced both motivation and attendance.ConclusionsThis study identified a range of different influences on decisions to attend a diabetes prevention programme, which programme organisers and healthcare professionals should consider to maximise attendance. Initial communication from general practitioners (GPs) and initial assessments are key points where people's beliefs and understanding could be explored.

\u2018Finishing the race\u2019 \u2013 a cohort study of weight and blood glucose change among the first 36,000 patients in a large-scale diabetes prevention programme

BackgroundThe NHS Diabetes Prevention Programme for England, “Healthier You”, encourages behaviour change regarding healthy eating and physical exercise among people identified to be at high risk of developing type 2 diabetes. The aim of this research was to examine change, and factors associated with change, in measures of HbA1c and weight in participants and completers of the programme between 2016 and 2019.MethodsParticipant-level data collected by programme service providers on referrals prior to March 2018 was analysed. Changes from baseline to both 6 months and completion in HbA1c and weight were examined using mixed effects linear regression, adjusting for patient characteristics, service provider and site.ResultsCompleters had average improvements in HbA1c of 2.1 mmol/mol [95% CI: − 2.2, − 2.0] (0.19% [95% CI: − 0.20, − 0.18]) and reductions of 3.6 kg [95% CI: − 3.6, − 3.5] in weight, in absolute terms. Variation across the four providers was observed at both time points: two providers had significantly smaller average reductions in HbA1c and one provider had a significantly smaller average reduction in weight compared to the other providers. At both time points, ex- or current smokers had smaller reductions in HbA1c than non-smokers and those from minority ethnic groups lost less weight than White participants. For both outcomes, associations with other factors were small or null and variation across sites remained after adjustment for provider and case mix.ConclusionsParticipants who completed the programme, on average, experienced improvements in weight and HbA1c. There was substantial variation in HbA1c change and smaller variation in weight loss between providers and across different sites. Aside from an association between HbA1c change and smoking, and between weight loss and ethnicity, results were broadly similar regardless of patient characteristics.

2020 NICE guideline update: Good news for pregnant women with type 1 diabetes and past or current gestational diabetes.

In December 2020, the National Institute for Health and Care Excellence (NICE) reviewed the evidence and updated their recommendations on intermittently scanned (commonly known as Flash) and Continuous Glucose Monitoring (CGM) during pregnancy for women with type 1 diabetes (1). The NICE guidelines now recommend offering CGM to all pregnant women with type 1 diabetes to help them meet their pregnancy glucose targets and improve neonatal outcomes. Their evidence review, based on the CONCEPTT randomised trial (2) and a Swedish observational study (3) found that, compared to capillary glucose monitoring, CGM resulted in more women achieving their blood glucose targets, fewer caesarean sections and fewer neonatal intensive care admissions.

A simulation study of the economic and health impact of a diabetes prevention programme in Ireland.

Type 2 diabetes is a major public health issue that has a large effect on society including its health and social services. The aims of this paper are to generate a projection of the number of cases and explore the potential impact of a preventive intervention targeted at people with pre-diabetes on disease prevalence, complications, mortality and cost. A Markov simulation model of diabetes and pre-diabetes in Ireland, for the period 1991 to 2036, was generated based on international epidemiological data. The simulation was calibrated with the available Irish data on the prevalence of pre-diabetes, diabetes and diabetic complications. The economic and health impact of a hypothetical nationwide preventive intervention programme, which reduces the incidence by a factor consistent with the international literature, was estimated under three scenarios of alternative effectiveness and uptake. The estimated number of people over 40years of age with type 2 diabetes in Ireland is projected to increase from 216,000 in 2020 to 414,000 in 2036. A prevention programme, based on the NHS Diabetes Prevention Programme, is estimated to result in a reduction of between 2000 (0.5%) and 19,000 (4.6%) in the number of prevalent cases of diabetes in 2036 resulting in substantial health and quality of life benefits. A wide range of initiatives with uncertain outcomes will be required to reduce the impact of obesity and type 2 diabetes. A diabetes prevention programme seems likely to be worth pursuing as one element of this set of initiatives.

Is the NHS Diabetes Prevention Programme Intervention Delivered as Planned? An Observational Study of Fidelity of Intervention Delivery.

BackgroundThe NHS Diabetes Prevention Programme (NHS-DPP) has been delivered by four commercial organizations across England, to prevent people with impaired glucose tolerance developing Type 2 diabetes. Evidence reviews underpinning the NHS-DPP design specification identified 19 Behavior Change Techniques (BCTs) that are the intervention “active ingredients.” It is important to understand the discrepancies between BCTs specified in design and BCTs actually delivered.PurposeTo compare observed fidelity of delivery of BCTs that were delivered to (a) the NHS-DPP design specification, and (b) the programme manuals of four provider organizations.MethodsAudio-recordings were made of complete delivery of NHS-DPP courses at eight diverse sites (two courses per provider organization). The eight courses consisted of 111 group sessions, with 409 patients and 35 facilitators. BCT Taxonomy v1 was used to reliably code the contents of NHS-DPP design specification documents, programme manuals for each provider organization, and observed NHS-DPP group sessions.ResultsThe NHS-DPP design specification indicated 19 BCTs that should be delivered, whereas only seven (37%) were delivered during the programme in all eight courses. By contrast, between 70% and 89% of BCTs specified in programme manuals were delivered. There was substantial under-delivery of BCTs that were designed to improve self-regulation of behavior, for example, those involving problem solving and self-monitoring of behavior.ConclusionsA lack of fidelity in delivery to the underlying evidence base was apparent, due to poor translation of design specification to programme manuals. By contrast, the fidelity of delivery to the programme manuals was relatively good. Future commissioning should focus on ensuring the evidence base is more accurately translated into the programme manual contents.

The NHS Diabetes Prevention Programme: an observational study of service delivery and patient experience

BackgroundThe NHS Diabetes Prevention Programme (NHS-DPP) is a nine-month, group-based behavioural intervention for adults in England at risk of developing Type 2 diabetes. Four independent providers were commissioned to deliver versions of the NHS-DPP, in line with NHS England specifications. This observational study maps NHS-DPP delivery in routine practice against the NHS specification, and compares service delivery with observed patient experiences.MethodsResearchers observed service delivery across eight complete NHS-DPP courses (118 sessions, median 14 sessions per course), consenting 455 participants (36 staff, 398 patients, 21 accompanying persons). Key features of NHS-DPP delivery were described using the Template for Intervention Description and Replication (TIDieR) framework. Researchers wrote detailed field notes during each session, including observations of patient experience. Field notes were content analysed; instances of positive and negative experiences were labelled and grouped into categories. Researchers used a novel method of comparing observed patient experiences to variations in programme delivery.ResultsDelivery broadly followed NHS England’s specification and the plans set out by providers. Deviations included the scheduling and larger group sizes in some sessions. There was variation in the type and format of activities delivered by providers. Positive patient experiences included engagement, satisfaction with the programme, good within-group relationships and reported behavioural changes. Negative experiences included poor scheduling, large groups, and dissatisfaction with the venue. Where more interactive and visual activities were delivered in smaller groups of 10–15 people with good rapport, there were generally more instances of positive patient experiences, and where there were structural issues such as problems with the scheduling of sessions, poor venues and inadequate resources, there tended to be more negative patient experiences.ConclusionsAddressing issues that we have identified as being linked to negative experiences with the NHS-DPP could increase uptake, reduce patient drop-out and increase the overall effectiveness of the programme. In particular, modifying structural aspects of the NHS-DPP (e.g. reliable session scheduling, reducing group sizes, enough session resources) and increasing interaction appear particularly promising for improving these outcomes.

Does the NHS Diabetes Prevention Programme prevent diabetes? A population-based matched cohort study

Abstract Background To reduce the incidence of type 2 diabetes (T2DM) in England, the National Health Service piloted the Diabetes Prevention Programme (DPP). The DPP aims to prevent T2DM by providing high-risk adults with access to 13 face-to-face sessions over nine months that focus on diet and weight management. The DPP has been shown to improve intermediate outcomes for T2DM prevention (weight loss and glycated haemoglobin (HbA1c) reduction). However, there is a lack of evidence examining incident T2DM as the outcome. Methods We conducted a retrospective observational cohort study using linked electronic health records from primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care for June 2016 to January 2019. We compared rates of new T2DM diagnoses among eligible adults who were referred to the DPP with rates for propensity score-matched (ratio of 1:4) controls who were eligible for the DPP but were not invited. DPP eligibility was defined as having HbA1c levels of 42-47 mmol/mol or fasting plasma glucose (FPG) levels of 5.5-6.9 mmol/L. Adults with pre-existing T2DM were excluded. Time to the first record of T2DM was modelled using Cox regression with age, alcohol intake, body mass index, ethnicity, sex, HbA1c, index of multiple deprivation and smoking status included as covariates. Results We identified 2205 individuals who participated in the DPP and 8820 matched controls with a similar breakdown in age, sex, HbA1c and FPG. During the 2.5-year study period, 4.13% of DPP individuals developed T2DM vs 6.42% of controls. Our results indicate that DPP referrals were associated with a 59% reduction T2DM incidence rates [adjusted hazard ratio=0.41;95%CI=0.38-0.44]. Conclusions This is the first study to investigate the impact of the DPP on T2DM, relative to usual care. Our results provide support for the effectiveness of DPP in preventing T2DM onset and are compatible with findings for similar interventions in other settings. Key messages The evidence suggests that providing consistent face-to-face sessions which concentrate on diet and weight management can reduce short-term T2DM incidences in high-risk adults. With a 59% reduction in T2DM rates in DPP referees relative to eligible adults who were not referred, the DPP is effective in reducing short-term T2DM incidences in high-risk adults.