GPs have been advised to review the care of thousands of patients after software used to assess cardiovascular risk has been found to have a flaw, it has been revealed.

Some 50,000 patients are set to have their cases reviewed, it has been reported.

The error has been found in the QRisk2 calculator in SystmOne software and dates back to 2009.

Practices have been contacted by the Medicines and Healthcare products Regulatory Agency to alert them to the problem.

According to one report, some 2,500 practices have been sent lists of about 20 patients affected by the error – which could affect decisions on whether to prescribe statins.

The MHRA has told GPs to cease using this piece of software – although they can use the original QRisk2 calculator, which is available on-line and is unaffected, it said.

An MHRA spokesman said: “The MHRA is working with TPP, the software provider, as a matter of urgency, to make sure the identified issue is resolved and that any affected patients are identified.

“Clinical advice is that the risk to patients is low and only a limited number of patients are potentially affected. GPs have been informed and they will contact individual patients should any further action be necessary.”

A Royal College of GPs spokesperson said: “Our patients should be reassured that the MHRA has said that the risk to patients is low, but any error in the technology we use to inform the advice we give our patients is very serious.

“We look to the MHRA for more information about how many patients are affected, and how they propose to minimise any risk to their safety.

“With statins being such a controversial treatment, among both doctors and patients, the seriousness of this error is particularly pronounced. The decision to prescribe statins to patients is never taken lightly, and those who are prescribed them will undertake regular medication reviews.”