A new programme of NHS Health Checks (NHSHC) was introduced in the UK in 2009. This aims to provide cardiovascular risk assessment every five years for adults aged 40-74 who are not already diagnosed with CVD or diabetes. The NHSHC offers a promising strategy for preventing CVD, yet several concerns have been raised in relation to its uptake, cost-effectiveness, success in reducing diseases and effectiveness of risk management. In this context, evaluation of the programme's longer-term outcomes is crucial. This study aims at evaluating changes in risk and cardiovascular clinical events and mortality outcomes following uptake of a health check. We will use a matched cohort design in the CPRD by comparing participants with a record of a complete NHSHC between 1st of April 2010 and 31st of March 2013 with follow-up data available for a minimum of three years after their health check up to 31st March 2016, together with matched control participants who did not receive a health check. We will adopt a time-to-event framework with date of check as the start date to evaluate the onset of new prescriptions. Hazard ratios will be estimated using the cox proportional hazards model and incident rate ratios using Poisson regression to examine the association between the programme and changes in clinical events and mortality.
Primary outcomes: Data will be analysed for changes in all-cause mortality and CHD and stroke clinical events, diabetes diagnosis and chronic kidney disease (CKD) diagnosis. Where feasible stroke will be classified as haemorrhagic or ischaemic. CHD events will be classified as angina, myocardial infarction, coronary artery bypass surgery or percutaneous coronary intervention and other. To ascertain cases of diabetes, diabetes drug prescriptions will be analysed by mapping drug codes to chapter subheadings in the British National Formulary. Medical diagnosis codes and levels of HbA1c levels (6.5%) will be analysed as well as diabetes diagnosis records. Medical diagnosis codes and levels of serum creatinine will be used to ascertain CKD cases. Secondary outcomes: CVD risk and CVD risk factors, including: smoking, BP, total cholesterol, HDL and BMI. Data on medication prescription for antihypertensive drugs, lipid-lowering drugs, antiplatelet drugs and nicotine replacement therapy will be analysed by recording drug codes to chapter subheadings in the British National Formulary.
Martin Gulliford - Chief Investigator - King's College London (KCL)
Samah Alageel - Corresponding Applicant - King's College London (KCL)