Cardiovascular events calculator: investigating the number of CV events avoided across England

Access the calculator at

In this first blog of the new decade, we thought we’d take a look back at the past five years of NHS Health Check provision and crunch some numbers regarding the quantity of cardiovascular (CV) events that the Programme has helped us to avoid. So that’s exactly what we did; in the process we produced a calculator so that you can do the same for your local authority area.

What does the calculator estimate?

The calculator shows the number of CV events that are estimated to have been avoided over the past 5 years due to statin prescriptions issued as a result of individuals having been identified as being at high risk following an NHS Health Check. Both national and local figures are accessible. As far as we at Health Diagnostics are aware, this is the first local calculator of its kind, though national-scale estimates have, in the past, been offered by researchers.

How accurate are these figures?

The number of CV events avoided as estimated by the calculator is likely to be extremely conservative; the overall figure is, in reality, probably much higher. This is due to various reasons such as:

  • The calculator does not account for the effects of behaviour change
  • The calculator only takes into account the effects of statin prescriptions (it does not factor in treatments such as anti-hypertensive medication)
  • The percentage of high risk may in fact be higher than researcher estimates (which are 10%; see reference to Robson et al)

Can I change the figures if I’ve got a clear idea of my local data?

You certainly can and we would encourage you to do so. For local authorities that Health Diagnostics support, we are able to establish this data from our intelligent data analytics services.

For example, in Kent County Council, we know that the estimated percentage of high-risk attendees is 15.9% (significantly higher than the researcher estimate of 10%). We also know that Kent’s local statin prescription rates marginally exceed the researcher data used by default within the calculator (19.4% rather than 19.3%).

If these refined figures are inputted into the calculator, a more accurate local account of the number of CV events avoided due to statin usage is produced; at least 100 CV events are likely to have been avoided in Kent over the past 5 years, rather than the 62 that would be estimated using default figures:

What are the estimations based on?

The calculator’s output is based on data from three main sources:

  1. Public Health England (PHE) data on the number of NHS Health Checks completed in each local authority over the past five years (Q1 2015/16 – Q2 2019/20). This data is submitted by each local authority to PHE and is published online.
  2. Figures used by Robson et al in their paper on ‘The NHS Health Check in England: an evaluation of the first 4 years’, published in BMJ Open (2016). By default, the calculator follows the researchers’ logic with respect to the number of individuals at high risk and prescribed statins.
  3. Data from a Cochrane systematic review investigating the effects of ‘Statins for the primary prevention of cardiovascular disease’. The data from this review is also that drawn on by Robson et al.

How can I get access?

Access the calculator at

Click the download link to access the Excel-based calculator. Having downloaded the calculator, you will need to enable the macros content with which this has been created, before being able to select your local authority area from the drop-down list, modify the figures as required, and view local estimates.

We hope you enjoy exploring the calculator. If you have any questions with regard to how this was produced or how Health Diagnostics establish refined local data, get in touch at