Researchers have developed a web calculator to identify patients at high-risk of adverse events from statins after a study found some may have unintended effects.

The study on statins, published in the BMJ, used the QResearch database of patients from UK GP practices to look at adverse outcomes from statins and found some can lead to an increased risk of liver dysfunction, acute renal failure, myopathy and cataracts.

Professor Julia Hippisley-Cox, professor of clinical epidemiology and general practice, and Carol Coupland, associate professor in medical statistics from Nottingham University, went on to develop algorithms so that the risk could be estimated for individual patients.

The algorithm is available online as a web calculator from www.qintervention.org. The researchers said it has been designed primarily for use by clinicians but can also be used by patients.

They said it could also be integrated into GP clinical computer systems to alert doctors to patients who might be at risk of adverse events and need closer monitoring.

The paper in the BMJ found that for every 10,000 women treated with statins, there would be approximately 271 fewer cases of cardiovascular disease and eight fewer cases of oesophageal cancer.

However, there would be 74 extra patents with liver dysfunction, 23 extra patients with renal failure, 307 extra patients with cataracts and 39 extra patients with myopathy.

The authors said: “At national level our study is likely to be useful for policy and planning purposes. Our study may also be useful for informing guidelines on the type and doses of statin.”

In an accompanying editorial in the BMJ two cardiologists say that statins are not entirely free of adverse events but that when used according to current guidelines the benefits outweigh the risks.”