External Validation of the Familial Hypercholesterolaemia Case Ascertainment Tool (FAMCAT)

Familial Hypercholesterolaemia (FH) is a common inherited cause of raised cholesterol, affecting up to 320,000 people in the UK. National Institute for Health and Care Excellence (NICE) guidance encourages identification of possible FH in primary care. However, over 80% of people with FH are still not identified, leading to many avoidable heart attacks and early deaths. The risk of heart disease can be dramatically reduced by starting medicines to lower cholesterol levels.

Currently it is recommended GPs identify possible FH by examining patients who have a raised cholesterol and a family history of heart disease. We have found this does not accurately identify all people with FH, and also causes unnecessary specialist referral for those without the condition.

Based on analysis using a large database of almost 3 million patients’ records (called the Clinical Practice Research Datalink or CPRD), including over 5000 cases of FH, we have developed a new computer-based approach to better identify people with possible FH. This uses information from GP computer records, and is called a FH case-ascertainment tool (or ‘FAMCAT’ for short).

We now need to test how valid and accurate FAMCAT is in predicting FH by using it in an entirely separate database. This has over 1 million patient records, set up by the Royal College of General Practitioners, using different general practices to those from the CPRD. This study will tell us how valid FAMCAT is when using information from different GPs and patient records. It will also help us identify any improvements that can be made to FAMCAT to further enhance its accuracy for use in health care.