Intelligent liver function testing

Research from the University of Dundee’s School of Medicine has led to the development of new, cost-effective pathways for the investigation of abnormal liver tests. The ‘intelligent Liver Function Test’ (iLFT) has improved patient outcomes and quality of care through the earlier diagnosis and treatment of liver disease.

Around 23.5 million liver function tests (LFTs) are conducted by GPs in the UK each year. LFTs can be used as a measure of general wellness but importantly the tests are also used to detect liver disease - now a leading cause of death in those aged under 65. An abnormal result offers an opportunity to follow-up with patients, allowing for the intervention and management of some of the most common causes at an early stage. Despite the common use of LFTs in General Practice, research led by Professor John Dillon uncovered  shortcomings in the follow-up of abnormal LFT results.

A series of studies examined integrated health data, looking at the investigation and management of abnormal test results. A retrospective study published in 2003, revealed limited follow-up of abnormal LFTs with identification of a specific liver disease occurring only in a small minority of cases, leading to subsequent negative effects on health resulting from late diagnosis.

An additional study in 2007 went on to examine the management of abnormal LFT findings in general practice, showing that despite abnormal results occurring in more than 20% of tests, over half of these were not investigated further. Of the patients who were investigated, 3% had liver disease with the potential to progress to life-limiting complications, highlighting the importance of timely investigation and treatment.

Further work identified the most common underlying causes of abnormal LFTs and led to the development of minimum diagnostic criteria for liver disease based on clinical information, making it possible to identify those at low risk of liver complications and enabling effective management through referral or through GPs.

The criteria have been used to create a system for automated diagnosis using equipment and platforms that are widely available in clinical laboratories. A single blood sample can be used to provide results that would previously have required up to six separate samples, with bloods directed through laboratory management systems using an intelligent liver function testing (iLFT) algorithm to generate one of 32 diagnostic outcomes and associated management plans.

The iLFT approach provides a rapid and reliable way to identify those results that require specialist follow-up. This has contributed to the better diagnosis of liver disease, often at an early stage when lifestyle interventions are effective, with minimum inconvenience to patients. It has also enabled identification of the highest priority patients, easing workload management for specialist hepatology services and assisting GPs in navigating appropriate diagnostic pathways.

Additional benefits have also been realised through the iLFT, as all samples are routinely tested for viral hepatitis. This has made it possible to identify unsuspected carriers of hepatitis C and target them for treatment, thereby preventing wider community transmission and contributing to the elimination of hepatitis C in Tayside by the end of 2019.

In August 2018, NHS Tayside adopted iLFT as standard care accessible to all its GP practices. During its first year, iLFT generated more than 2000 diagnoses from 1824 samples with an abnormal result from initial LFTs. Following this success in Tayside, the Scottish Access Collaborative (part of the Scottish Government’s Directorate for Health Performance and Delivery) has recommended national rollout. The Lancet Commission for Liver Disease has recommended iLFT for implementation, and it is being adopted across the UK.

The iLFT has been recognised for its excellence, winning awards for achievements in integrated clinical care through the UNIVANTS Healthcare Excellence Award as well as accolades for innovation from the British Society of Gastroenterology and the Royal Colleges of Physicians and Pathologists.

Read more about research impact in the School of Medicine