Launched in 2009, the NHS Health Check (NHSHC) is a public health intervention aimed at identifying patients who have a high risk of developing Heart Disease, Diabetes, Kidney Disease and Stroke. The NHSHC helps patients manage their risk by referring them to programmes aimed at enabling lifestyle changes. However, there is no definitive research into the NHSHC's effectiveness with studies suggesting that similar programmes have negligible impact on healthcare outcomes. There is currently a lack of evidence evaluating the NHSHC, leading academics to demand more research. Whilst research has contributed information on the uptake of the NHSHC, these studies have not evaluated the long-term diabetic outcomes between participants and non-participants of the NHSHC. Using the Clinical Practice Research Datalink (CPRD), we will filter those who are eligible for the NHSHC and from this subset, we will classify patients by participation status. We will then compare Diabetic outcomes (e.g. a diagnosis for Diabetes including Chronic Kidney Disease, Diabetic Retinopathy, Diabetic Foots complications and diabetic related deaths) between eligible patients who did and did not have an NHSHC. To generalise our findings, we will replicate this study with the NHS Diabetes Prevention Programme (NHSDPP) data to evaluate Public Health Intervention's effect on Diabetic healthcare outcomes.
Background: The NHSHC and DPP are expensive population-level interventions without strong trial-based evidence of effectiveness. Observational studies are prone to problems such as missing data, confounding and selection biases. We will evaluate the effectiveness of the programmes and compare the influence of different analytical techniques to inform future design of observational studies.
Methods: Study design: Two Retrospective Cohort studies assessing effectiveness of a) NHSC and b) DPP on diabetes health outcomes.
Target populations: those eligible for a) NHSHC (2009-16) and b) DPP (2016-2018) identified through demographic and READ code variables in Up to Standard CPRD practices.
Intervention identification: Dedicated READ codes for the NHSHC/DPP supplemented by previously established algorithms for the NHSHC.
Outcomes: Incidence of Diabetes diagnosis, HbA1c, Chronic Kidney Disease, Retinopathy and Foot Complications up to 5 years following the health checks.
Covariates include: Urinary Albumin levels, Framingham Score, and BMI.
Analytical approaches: Our primary approach is to use multiple imputation for missing data and propensity score matching (PSM) to ensure similarity of "treated" (i.e. those undergoing interventions within the programme) and "untreated" groups.
We will undertake a variety of classical and emerging epidemiological approaches to missing data, confounding and selection bias and compare predictive power of different approaches.
HbA1c levels
- Vascular complications including amputations
- T2DM Incidence
- Diabetic Retinopathy incidences
- Avoidable mortality associated with Diabetes
Robert Aldridge - Chief Investigator - University College London ( UCL )
Vincent Nguyen - Corresponding Applicant - University College London ( UCL )
Andrew Hayward - Collaborator - University College London ( UCL )
Felix Greaves - Collaborator - Public Health England
Hannah Evans - Collaborator - University College London ( UCL )
Julian Flowers - Collaborator - Public Health England
Ruth Blackburn - Collaborator - University College London ( UCL )
HES Accident and Emergency;HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation