Analysis of an Indian diabetes prevention programme on association of adipokines and a hepatokine with incident diabetes

To study the association and possible predictive role of visfatin, resistin, fetuin-A and chemerin with incident type 2 diabetes (T2DM) among Asian Indians with prediabetes. Their association with insulin resistance, β-cell function, glycaemia and anthropometry were also studied. This is a nested case–control study of a large 2-year prospective prevention trial in persons at high risk of developing T2DM. Baseline HbA1c values between 6.0% (42 mmol/mol) and 6.2% (44 mmol/mol) were chosen for this analysis (n = 144). At follow-up, persons with incident T2DM (HbA1c ≥ 6.5%, 48 mmol/mol) were grouped as cases (n = 72) and those reverted to normoglycaemia, (HbA1c < 5.7% (39 mmol/mol) as controls (n = 72). Insulin resistance showed the strongest association with incident T2DM ((Odds Ratio (OR): 23.22 [95%CI 6.36–84.77]; p < 0.0001). Baseline visfatin (OR: 6.56 [95%CI 2.21–19.5]; p < 0.001) and fetuin-A (OR: 1.01 [95%CI (1.01–1.04)]; p < 0.0001) independently contributed to the conversion of prediabetes to T2DM. The contribution was significantly higher when their elevated levels coexisted (OR: 12.63 [95%CI 3.57–44.63]; p < 0.0001). The area under the curve was 0.77 ± SE 0.4 (95%CI 0.69–0.85) and 0.80 ± SE 0.04 (95%CI 0.73–0.88) for visfatin (median 17.7 ng/ml, sensitivity and specificity: 75%, p < 0.0001) and fetuin-A (mean 236.2 µg/ml, sensitivity: 71%, specificity: 75%, p < 0.0001) respectively. Higher baseline visfatin and fetuin-A concentrations are strongly associated with incident T2DM and are predictive of future diabetes.

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

Background It 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. Methods A 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. Results The 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. Conclusions A 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.

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

Background The 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. Purpose To 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. Methods Audio-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. Results The 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. Conclusions A 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 Fidelity of Training in Behaviour Change Techniques to Intervention Design in a National Diabetes Prevention Programme

Background The 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. Method One 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. Results Ten 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. Conclusion Observed 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.