National Health Service Diabetes 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.

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

BackgroundWe 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.MethodsWe 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.ResultsRisk 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).ConclusionsReducing 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.

The effectiveness of digital delivery versus group-based face-to-face delivery of the English National Health Service Type 2 Diabetes Prevention Programme: a non-inferiority retrospective cohort comparison study

BackgroundFace-to-face group-based diabetes prevention programmes have been shown to be effective in many settings. Digital delivery may suit some patients, but research comparing the effectiveness of digital with face-to-face delivery is scarce. The aim was to assess if digital delivery of the English National Health Service Diabetes Prevention Programme (NHS DPP) is non-inferior to group-based face-to-face delivery in terms of weight change, and evaluate factors associated with differential change.MethodsThe study included those recruited to the NHS DPP in 2017–2018. Individual-level data from a face-to-face cohort was compared to two cohorts on a digital pilot who (i) were offered no choice of delivery mode, or (ii) chose digital over face-to-face. Changes in weight at 6 and 12 months were analysed using mixed effects linear regression, having matched participants from the digital pilot to similar participants from face-to-face.ResultsWeight change on the digital pilot was non-inferior to face-to-face at both time points: it was similar in the comparison of those with no choice (difference in weight change: -0.284 kg [95% CI: -0.712, 0.144] at 6 months) and greater in digital when participants were offered a choice (-1.165 kg [95% CI: -1.841, -0.489]). Interactions between delivery mode and sex, ethnicity, age and deprivation were observed.ConclusionsDigital delivery of the NHS DPP achieved weight loss at least as good as face-to-face. Patients who were offered a choice and opted for digital experienced better weight loss, compared to patients offered face-to-face only.

A qualitative evaluation of the national rollout of a diabetes prevention programme in England

BackgroundThe National Health Service Diabetes Prevention Programme (NHS DPP) was commissioned by NHS England in 2016 and rolled out in three ‘waves’ across the whole of England. It aims to help people with raised blood glucose levels reduce their risk of developing type 2 diabetes through behaviour change techniques (e.g., weight loss, dietary changes and exercise). An independent, longitudinal, mixed methods evaluation of the NHS DPP was undertaken. We report the findings from the implementation work package: a qualitative interview study with designated local leads, responsible for the local commissioning and implementation of the programme. The aim of the study was to explore how local implementation processes were enacted and adapted over time.MethodsWe conducted a telephone interview study across two time-points. Twenty-four semi-structured interviews with local leads across 19 sampled case sites were undertaken between October 2019 and January 2020 and 13 interviews with local leads across 13 sampled case sites were conducted between July 2020 and August 2020. Interviews aimed to reflect on the experience of implementation and explore how things changed over time.ResultsWe identified four overarching themes to show how implementation was locally enacted and adapted across the sampled case sites: 1. Adapting to provider change; 2. Identification and referral; 3. Enhancing uptake in underserved populations; and 4. Digital and remote service options.ConclusionThis paper reports how designated local leads, responsible for local implementation of the NHS DPP, adapted implementation efforts over the course of a changing national diabetes prevention programme, including how local leads adapted implementation during the COVID-19 pandemic. This paper highlights three main factors that influence implementation: the importance of facilitation, the ability (or not) to tailor interventions to local needs and the role of context in implementation.

Flash glucose monitoring in young people with type 1 diabetes—a qualitative study of young people, parents and health professionals: ‘It makes life much easier’

ObjectivesFlash glucose monitoring for patients with T1 diabetes avoids frequent painful finger-prick testing, thus potentially improving frequency of glucose self-monitoring. Our study aimed to explore experiences of young people using...

Comparison of weight change between face-to-face and digital delivery of the English National Health service diabetes prevention programme: An exploratory non-inferiority study with imputation of plausible weight outcomes

Worldwide evidence suggests face-to-face diabetes prevention programmes are effective in preventing and delaying the onset of type 2 diabetes by encouraging behaviour change towards weight loss, healthy eating, and increased exercise. There is an absence of evidence on whether digital delivery is as effective as face-to-face. During 2017–18 patients in England were offered the National Health Service Diabetes Prevention Programme as group-based face-to-face delivery, digital delivery (‘digital-only’) or a choice between digital and face-to-face (‘digital-choice’). The contemporaneous delivery allowed for a robust non-inferiority study, comparing face-to-face with digital only and digital choice cohorts.Changes in weight at 6 months were missing for around half of participants. Here we take a novel approach, estimating the average effect in all 65,741 individuals who enrolled in the programme, by making a range of plausible assumptions about weight change in individuals who did not provide outcome data. The benefit of this approach is that it includes everyone who enrolled in the programme, not restricted to those who completed. We analysed the data using multiple linear regression models.Under all scenarios explored, enrolment in the digital diabetes prevention programme was associated with clinically significant reductions in weight which were at least equivalent to weight loss in the face-to-face programme. Digital services can be just as effective as face-to-face in delivering a population-based approach to the prevention of type 2 diabetes. Imputation of plausible outcomes is a feasible methodological approach, suitable for analysis of routine data in settings where outcomes are missing for non-attenders.

The English national health service diabetes prevention programme (NHS DPP): A scoping review of existing evidence

AimsThe English National Health Service Diabetes Prevention Programme (NHS DPP) is commissioned by NHS England and has been rolled out across England to adults identified as being at high risk of type 2 diabetes. The present scoping review aimed to identify the extent and nature of evidence to date on the NHS DPP and describe what the evidence has reported.MethodsA scoping review involving searches of various sources (including MEDLINE, CINAHL, MediArXiv, Google Scholar and GreyLit) was conducted on 31 August 2021 and repeated on 09 February 2022. Only articles reporting on the NHS DPP made available since 2015 were eligible for inclusion.Results65 articles were included. Of these, 37 were journal publications. Most articles were made available in 2018 and 2020 (total n = 25). The majority of articles reported on uptake and retention (n = 27) whilst others reported on implementation considerations (n = 24), programme outcomes (n = 21), stakeholder experience (n = 8) and screening and referral processes (n = 3). Various research methods were reported and included qualitative (n = 9) and document analysis (n = 8). Articles revealed preliminary evidence on service user characteristics, rates of referral, uptake and retention as well as how far the NHS DPP is being delivered in line with its evidence base and service specification.ConclusionsThe evidence is accumulating on NHS DPP uptake and retention most, with emerging evidence on programme outcomes (such as weight loss and HbA1c). More evidence is warranted on stakeholder experience to decipher how to overcome low initial and long‐term engagement reported by the current evidence base.

How is the Behavior Change Technique Content of the NHS Diabetes Prevention Program Understood by Participants? A Qualitative Study of Fidelity, With a Focus on Receipt.

BackgroundThe National Health Service (NHS) Diabetes Prevention Program (DPP) is a nationally implemented behavioral intervention for adults at high risk of developing Type 2 diabetes in England, based on a program specification that stipulates inclusion of 19 specific behavior change techniques (BCTs). Previous work has identified drift in fidelity from these NHS England specifications through providers’ program manuals, training, and delivery, especially in relation to BCTs targeting self-regulatory processes.PurposeThis qualitative study investigates intervention receipt, i.e., how the self-regulatory BCT content of the NHS-DPP is understood by participants.MethodsTwenty participants from eight NHS-DPP locations were interviewed; topics included participants’ understanding of self-monitoring of behavior, goal setting, feedback, problem solving, and action planning. Transcripts were analyzed thematically using the framework method.ResultsThere was a wide variation in understanding among participants for some BCTs, as well as between BCTs. Participants described their understanding of “self-monitoring of behaviors” with ease and valued BCTs focused on outcomes (weight loss). Some participants learned how to set appropriate behavioral goals. Participants struggled to recall “action planning” or “problem solving” or found these techniques challenging to understand, unless additional support was provided (e.g., through group discussion).ConclusionsParticipants’ lack of understanding of some self-regulatory BCTs is consistent with the drift across fidelity domains previously identified from NHS design specifications. Behavioral interventions should build-in necessary support for participants to help them understand some BCTs such as action planning and problem solving. Alternatively, these self-regulatory BCTs may be intrinsically difficult to use for this population.

The theoretical basis of a nationally implemented type 2 diabetes prevention programme: how is the programme expected to produce changes in behaviour?

BackgroundIt is considered best practice to provide clear theoretical descriptions of how behaviour change interventions should produce changes in behaviour. Commissioners of the National Health Service Diabetes Prevention Programme (NHS-DPP) specified that the four independent provider organisations must explicitly describe the behaviour change theory underpinning their interventions. The nationally implemented programme, launched in 2016, aims to prevent progression to Type 2 diabetes in high-risk adults through changing diet and physical activity behaviours. This study aimed to: (a) develop a logic model describing how the NHS-DPP is expected to work, and (b) document the behaviour change theories underpinning providers’ NHS-DPP interventions.MethodsA logic model detailing how the programme should work in changing diet and activity behaviours was extracted from information in three specification documents underpinning the NHS-DPP. To establish how each of the four providers expected their interventions to produce behavioural changes, information was extracted from their programme plans, staff training materials, and audio-recorded observations of mandatory staff training courses attended in 2018. All materials were coded using Michie and Prestwich’s Theory Coding Scheme.ResultsThe NHS-DPP logic model included information provision to lead to behaviour change intentions, followed by a self-regulatory cycle including action planning and monitoring behaviour. None of the providers described an explicit logic model of how their programme will produce behavioural changes. Two providers stated their programmes were informed by the COM-B (Capability Opportunity Motivation – Behaviour) framework, the other two described targeting factors from multiple theories such as Self-Regulation Theory and Self-Determination Theory. All providers cited examples of proposed links between some theoretical constructs and behaviour change techniques (BCTs), but none linked all BCTs to specified constructs. Some discrepancies were noted between the theory described in providers’ programme plans and theory described in staff training.ConclusionsA variety of behaviour change theories were used by each provider. This may explain the variation between providers in BCTs selected in intervention design, and the mismatch between theory described in providers’ programme plans and staff training. Without a logic model describing how they expect their interventions to work, justification for intervention contents in providers’ programmes is not clear.

The Fidelity of Training in Behaviour Change Techniques to Intervention Design in a National Diabetes Prevention Programme

BackgroundThe National Health Service Diabetes Prevention Programme (NHS-DPP) is a behavioural intervention for people identified as high risk for developing type 2 diabetes that has been rolled out across England. The present study evaluates whether the four commercial providers of the NHS-DPP train staff to deliver behaviour change technique (BCT) content with fidelity to intervention plans.MethodOne set of mandatory training courses across the four NHS-DPP providers (seven courses across 13 days) was audio-recorded, and all additional training materials used were collected. Recordings and training materials were coded for BCT content using the BCT Taxonomy v1. BCTs and depth of training (e.g. instruction, demonstration, practice) of BCT content was checked against providers’ intervention plans.ResultsTen trainers and 78 trainees were observed, and 12 documents examined. The number of unique BCTs in audio recordings and associated training materials ranged from 19 to 44 across providers, and staff were trained in 53 unique BCTs across the whole NHS-DPP. Staff were trained in 66% of BCTs that were in intervention plans, though two providers trained staff in approximately half of BCTs to be delivered. The most common way that staff were trained in BCT delivery was through instruction. Training delivery style (e.g. experiential versus educational) varied between providers.ConclusionObserved training evidences dilution from providers’ intervention plans. NHS-DPP providers should review their training to ensure staff are trained in all key intervention components, ensuring thorough training of BCTs (e.g. demonstrating and practicing how to deliver) to enhance BCT delivery.

An evaluation of goal setting in the NHS England diabetes prevention programme

Objective We know little about how goal setting is actually delivered in routine practice. The National Health Service Diabetes Prevention Programme (NHS-DPP) is a behavioural intervention aiming to prevent progression to Type 2 diabetes in those at risk. It has been delivered across England by four commercial providers. This study aimed to establish whether goal setting in the NHS-DPP was delivered in line with the current evidence base. Design: Observational study and document review. One-hundred-and-eighteen NHS-DPP sessions with 419 people were observed at eight sites (two sites per provider). Main outcome measures: Multiple characteristics of goal setting were reliably coded from each providers’ programme plans (intended goal setting) and from audio-recorded NHS-DPP sessions (actual goal setting). Results: Providers intended to deliver goal setting in 88.3% of sessions, though goal setting was delivered in only 52.5% of sessions. During delivery, the observed goals set across providers were generally specific (62.5%), set privately (53.1%), with goal difficulty rarely mentioned (3.1%). Conclusions: Goal setting in the NHS-DPP is being under-delivered, and not in line with the evidence base for promoting behavioural change. Goal setting in national behaviour change programmes should be optimised and training provided specifically for goal setting.

Experience of point-of-care HbA1c testing in the English National Health Service Diabetes Prevention Programme: an observational study

IntroductionTo report the observations of point-of-care (POC) glycated hemoglobin (HbA1c) testing in people with non-diabetic hyperglycemia (NDH; HbA1c 42–47 mmol/mol (6.0%–6.4%)), applied in community settings, within the English National Health...

Prediction of type 2 diabetes risk in people with non-diabetic hyperglycaemia: model derivation and validation using UK primary care data

ObjectiveUsing primary care data, develop and validate sex-specific prognostic models that estimate the 10-year risk of people with non-diabetic hyperglycaemia developing type 2 diabetes.DesignRetrospective cohort study.SettingPrimary care.Participants154 705 adult patients...

The Impact of Including Costs and Outcomes of Dementia in a Health Economic Model to Evaluate Lifestyle Interventions to Prevent Diabetes and Cardiovascular Disease.

ObjectivesEconomic evaluations of lifestyle interventions, which aim to prevent diabetes/cardiovascular disease (CVD), have not included dementia. Lifestyle interventions decrease dementia risk and extend life expectancy, leading to competing effects on health care costs. We aim to demonstrate the feasibility of including dementia in a public health cost-effectiveness analysis and quantify the overall impacts accounting for these competing effects.MethodsThe School for Public Health Research (SPHR) diabetes prevention model describes individuals’ risk of type 2 diabetes, microvascular outcomes, CVD, congestive heart failure, cancer, osteoarthritis, depression, and mortality in England. In version 3.1, we adapted the model to include dementia using published data from primary care databases, health surveys, and trials of dementia to describe dementia incidence, diagnosis, and disease progression. We estimate the impact of dementia on lifetime costs and quality-adjusted life years (QALYs) gained of the National Health Service diabetes prevention program (NHS DPP) from an NHS/personal social services perspective with 3 scenarios: 1) no dementia, 2) dementia only, and 3) reduced dementia risk. Subgroup, parameter, and probabilistic sensitivity analyses were conducted.ResultsThe lifetime cost savings of the NHS DPP per patient were £145 in the no-dementia scenario, £121 in the dementia-only scenario, and £167 in the reduced dementia risk scenario. The QALY gains increased by 0.0006 in dementia only and 0.0134 in reduced dementia risk. Dementia did not alter the recommendation that the NHS/DPP is cost-effective.ConclusionsIncluding dementia into a model of lifestyle interventions was feasible but did not change policy recommendations or modify health economic outcomes. The impact on health economic outcomes was largest where a direct impact on dementia incidence was assumed, particularly in elderly populations.

Stakeholders\u2019 perceptions and experiences of the National Health Service diabetes prevention programme in England: qualitative study with service users, intervention providers and deliverers, commissioners and referrers

BackgroundThe National Health Service diabetes prevention programme in England, (NHS DPP) aims to identify people at high risk of type 2 diabetes (T2D) and offer them a face-to-face, group-based, behaviour change intervention for at least 9 months. The NHS DPP was rolled out in phases. We aimed to elicit stakeholders’ perceptions and experiences of the factors influencing implementation of, and participation in, the programme during the development phase.MethodsIndividual, semi-structured telephone interviews were conducted with 50 purposively sampled stakeholders: service users (n = 20); programme commissioners (n = 7); referrers (n = 8); and intervention deliverers (n = 15). Topic guides were structured using a pragmatic, theory-informed approach. Analysis employed the framework method.ResultsWe identified factors that influenced participation: Risk communication at referral - stakeholders identified point of referral as a window of opportunity to offer brief advice, to provide an understanding of T2D risk and information about the programme; Perceived impact of the NHS DPP - service users highlighted the positive perceived impact on their behaviour change, the peer support provided by participating in the programme, the option to involve a relative, and the ‘knock on’ effect on others. Service users also voiced disappointment when blood test results still identified them at high risk after the programme; and Behavioural maintenance - participants highlighted the challenges linked to behavioural maintenance (e.g. discontinuation of active support). Factors influencing implementations were also identified: Case finding – stakeholders suggested that using community involvement to identify service users could increase reach and ensure that the workload was not solely on GP practices; Adaptability: intervention deliverers acknowledged the need to tailor advice to service users’ preferences and needs; Accountability – the need to acknowledge who was responsible for what at different stages of the NHS DPP pathway; and Fidelity – stakeholders described procedures involved in monitoring service users’ satisfaction, outcome data collection and quality assurance assessments.ConclusionsThe NHS DPP offers an evidence-informed behavioural intervention for T2D prevention. Better risk communication specification could ensure consistency at the referral stage and improve participation in the NHS DPP intervention. Cultural adaptations and outreach strategies could ensure the NHS DPP contributes to reducing health inequalities.

Early Outcomes From the English National Health Service Diabetes Prevention Programme

To assess weight and HbA1c changes in the Healthier You: National Health Service Diabetes Prevention Programme (NHS DPP), the largest DPP globally to achieve universal population coverage. A service evaluation assessed intervention effectiveness for adults with nondiabetic hyperglycemia (HbA1c 42-47 mmol/mol [6.0-6.4%] or fasting plasma glucose 5.5-6.9 mmol/L) between program launch in June 2016 and December 2018, using prospectively collected, national service-level data in England. By December 2018, 324,699 people had been referred, 152,294 had attended the initial assessment, and 96,442 had attended at least 1 of 13 group-based intervention sessions. Allowing sufficient time to elapse, 53% attended an initial assessment, 36% attended at least one group-based session, and 19% completed the intervention (attended >60% of sessions). Of the 32,665 who attended at least one intervention session and had sufficient time to finish, 17,252 (53%) completed: intention-to-treat analyses demonstrated a mean weight loss of 2.3 kg (95% CI 2.2, 2.3) and an HbA1c reduction of 1.26 mmol/mol (1.20, 1.31) (0.12% [0.11, 0.12]); completer analysis demonstrated a mean weight loss of 3.3 kg (3.2, 3.4) and an HbA1c reduction of 2.04 mmol/mol (1.96, 2.12) (0.19% [0.18, 0.19]). Younger age, female sex, Asian and black ethnicity, lower socioeconomic status, and normal baseline BMI were associated with less weight loss. Older age, female sex, black ethnicity, lower socioeconomic status, and baseline overweight and obesity were associated with a smaller HbA1c reduction. Reductions in weight and HbA1c compare favorably with those reported in recent meta-analyses of pragmatic studies and suggest likely future reductions in participant type 2 diabetes incidence.

Oral presentationsSystematic review of the factors associated with health behaviours related to obesity among refugee childrenPreliminary development of quality of life scales for children and adults with Niemann-Pick Type CThe diversity of diabetes-related self-monitoring and problem-solving practices across health literacy levels: An interview studyResilience as a predictor of burnout, depression and hope among medical studentsThe lived experience of parents with

In order of first author surname

NHS Diabetes Prevention Programme in England: formative evaluation of the programme in early phase implementation

ObjectivesEvaluation of the demonstrator phase and first wave roll-out of the National Health Service (NHS) Diabetes Prevention Programme (DPP) in England. To examine: (1) intervention design, provision and fidelity assessment...

Assessing the potential return on investment of the proposed UK NHS diabetes prevention programme in different population subgroups: an economic evaluation

ObjectivesTo evaluate potential return on investment of the National Health Service Diabetes Prevention Programme (NHS DPP) in England and estimate which population subgroups are likely to benefit most in terms...

Radically upgrading diabetes prevention in England

3 million people in England currently have type 2 diabetes. 1 Health and Social Care Information CentreQuality and outcomes framework—2012–13. http://www.hscic.gov.uk/catalogue/PUB12262 Google Scholar Estimates suggest that diabetes consumes almost 10% of the UK National Health Service (NHS) budget—about £9 billion annually—and is responsible for more than 100 amputations every week and 20 000 early deaths every year. 2 Health and Social Care Information CentreNational diabetes audit—2011–12. http://www.hscic.gov.uk/catalogue/PUB12421 Google Scholar , 3 Hex N Bartlett C Wright D Taylor M Varley D Estimating the current and future costs of type 1 and type 2 diabetes in the United Kingdom, including direct health costs and indirect societal and productivity costs. Diabetic Med. 2012; 29: 855-862 Crossref PubMed Scopus (555) Google Scholar This burden, although largely preventable, is increasing; by 2025 an estimated 4 million people will have diabetes. 4 Public Health EnglandDiabetes prevalence model (APHO). http://www.yhpho.org.uk/resource/view.aspx?RID=81090 Google Scholar The health and economic rationale for prevention is clear. Diabetes prevention in England – Authors' replyWe thank John Yudkin and Christopher Millett for their correspondence. We agree that radically upgrading prevention will require a whole-society approach, with alteration of environmental and contextual factors, supporting people in achieving improved dietary intake and increased physical activity. Supporting this societal approach, local authorities now have a statutory responsibility for improving health, and councils and elected mayors are able to make an important impact. For example, the London Borough of Barking and Dagenham are seeking to limit new junk food outlets near schools. Full-Text PDF Diabetes prevention in EnglandThe announcement of NHS England's National NHS Diabetes Prevention Programme1 (DPP) comes just weeks after Nicholas Wareham's warning2 about the “achievability gap” in attempts to roll out lifestyle approaches used in the original DPP study.3 Preventing diabetes, moreover, is qualitatively different from preventing cancer. Glycaemia is a continuous variable, with an HbA1c cutpoint of 6·5%, or a fasting glucose of 7·0mmol/L, as the diagnostic threshold. Interventions in the DPP study simply delayed crossing this threshold by 2–4 years,4 with reduction in levels of HbA1c of 0·1–0·2% over 10 years, less than one-fifth of that achieved during the UK Prospective Diabetes Study. Full-Text PDF