Conveying the concept of risk

Former president of the Primary Care Cardiovascular Society and practice nurse Jan Procter-King on how to explain the complex concepts of CV risk to patients

Assessing cardiovascular risk is part of the everyday workload for GPs and is done using well-validated, well-used algorithms. Conveying that risk to patients requires a different set of skills, but doing so effectively will increase the chance of any prescribed treatment being taken.

One 2007 study looking at how statin adherence could be improved found that simplified drug regimens and patient education were among the strategies that showed the most promise.1

In 2010, another study showed that giving patients an idea of the risk of heart disease in a way they could easily understand and digest could motivate those at moderate to high risk to take medication.2

Graphical versus numerical risk

Having collected the appropriate data and fed it into the risk engine you use – QRISK, Framingham or possibly ASSIGN, if you practise in Scotland – a percentage risk for that individual will be generated.

This number represents that individual's percentage chance of developing cardiovascular disease in the next 10 years.

The concept of risk is difficult to grasp, and you could explain it to a patient by saying something such as: ‘In other words, in a crowd of 100 people who are similar to you, this is how many will develop heart disease or have a stroke or TIA in the next 10 years.'

But a chart of one hundred hearts or faces – if appropriately used – is a really useful tool when advising an individual.

In fact, a 2008 study looked at the best way to convey cardiovascular benefit from treatment by expressing it numerically – relative risk, absolute risk, number needed to treat, odds ratio – and graphically.3

Although NNT was found to be a useful tool for communicating risk and benefit to clinicians, it was the least likely to encourage patients to take medication. A graphical representation of benefit was the method patients preferred most.

Conveying reduction in risk

If explaining a patient's risk of a cardiovascular event to them is a challenge, then conveying the idea of a likely risk reduction is even more so.

If someone takes the therapeutic dose of a statin, their cardiovascular risk reduction is estimated at 25% – a statistic often bandied about. But what does it mean, and how can we explain it to patients?

Take the example of someone calculated as having a risk level of 8%. You could show patients a visual of 100 hearts with eight cracked, and two of those eight mended again, but at this level it is debatable whether most would take a tablet every day for the rest of their foreseeable lives – and indeed, they would be below the threshold for statin treatment.

But at the nationally agreed threshold for treatment of 20% risk – 100 hearts, with 20 broken and five of those mended – it is likely to be a different discussion. And when you get to 40% the benefit will seem that much more worth the inconvenience and effort of taking a statin.

You can also use free websites to do much the same thing (see further information below).

We are not psychic, and all we can do is help patients considering taking a statin to be aware of the data as we understand it, with the implication that hopefully they will be the one who benefits.

But I often use a chart like the one below to try and help them make that decision.

I explain that if all 100 took the statin every day, a quarter of those at risk would not suffer from a heart attack, angina or stroke. I then draw:

• a circle around one of the patients who was never going to suffer a cardiovascular event with or without a statin, but they took a statin anyway (a whole heart)

• a circle around one who still got diagnosed with CVD even though they had taken a statin (a broken heart)

• a circle around one who didn't suffer an event because they took a statin (a healed heart).

Having explained these possibilities, I ask if the patient has any questions, then ask what they think. This is the clearest way I know to help patients visualise the three possible scenarios, and so far I have been pleasantly surprised that people appreciate the honesty and feel more able to make an informed decision.

Statins do not remove risk, but do reduce it. If we are going to ask people to pay for their prescription, remember to take a tablet every day and include this on every insurance form they complete, it's only reasonable to let them decide with the clearest perception possible of their risk and the impact a statin could have on their future.

Finally, it might be worth considering who does risk assessment in your practice. If it's a practice nurse or healthcare assistant, check if they have sufficient experience to appreciate and explain the concept of reducing risk.

Jan Procter-King is a primary care CVD nurse, former president of the PCCS and lead CVD tutor for the Primary Care Training Centre in Bradford