The identification of chronic liver disease in primary care using non-invasive diagnostics within a novel pathway

• Main Author: Harman, David J.
• Published: University of Nottingham 2017
• Subjects: 362.1963; WI Digestive system
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.719407

Introduction: Deaths due to chronic liver disease have increased significantly in recent decades. This is due to increases in alcohol consumption and obesity during this time period, and insensitive screening tests (liver function blood tests) utilised in primary care. This thesis describes a new liver disease community diagnostic pathway which focussed upon defined risk factors for chronic liver disease and uses Transient Elastography (TE) as the primary investigation modality. The aims of the thesis are to assess the feasibility of this pathway for detecting liver disease due to alcohol or non-alcoholic fatty liver disease within the United Kingdom healthcare system, to quantify the number of new cases detected with this approach and to evaluate patient experience of these investigations. Methods: Following a systematic review of the literature, an investigation pathway was derived and piloted in 4 general practice sites in Nottinghamshire in two phases between February 2012 and September 2014. Patients with hazardous alcohol use, type 2 diabetes or persistently raised alanine aminotransferase (ALT) level and negative liver serology were eligible for study. TE was performed in the community; a liver stiffness reading of ≥8 kilopascals defined clinically significant liver disease and subsequent review in a consultant led community clinic. Risk factors for new diagnoses of liver disease and cirrhosis were identified and the association with obesity investigated. A qualitative interview substudy was conducted to explore the experiences of 20 patients undergoing investigation. Results: In a total adult population of 20,868 patients, 2,022 patients were eligible for study of whom 909 (45%) underwent TE. Valid liver stiffness measurements were possible in 98% of patients. Overall, 230 cases of elevated liver stiffness and 27 new cases of cirrhosis were identified. Minimum cirrhosis prevalence in patients with type 2 diabetes was 2%. Obesity was significantly associated with diagnosis of cirrhosis in type 2 diabetics (odds ratio 9.4 (95% CI 2.2-40.9)) and hazardous alcohol users (OR 5.6 (95% CI 1.6-19.7)). The majority of new cases of liver disease had normal ALT levels. From the initial pilot phase in two general practices in Rushcliffe (Nottingham), in which liver function test data from 378 patients undergoing TE was analysed, 72.4% with elevated liver stiffness measurement, 60% with biopsy proven cirrhosis and 90% with cirrhosis diagnosis had normal ALT. Patients felt that TE was a useful adjunct to lifestyle change and described a positive experience of liver disease investigation. Conclusion: A new non-invasive diagnostic pathway for liver disease was feasible to implement in Nottinghamshire primary care and resulted in significantly increased diagnosis of chronic liver disease and cirrhosis. These findings warrant exploration of the pathway in a larger primary care population.