Sattar and colleagues review the epidemiology, manifestations and management of of non-alcoholic fatty liver disease . Their recommendations include the need to consider screening for other liver conditions such as chronic viral hepatitis, autoimmune liver disease, haemochromatosis, or drug induced liver injury. The value and cost implications of routine screening for rarer causes of liver disease in individuals with abnormal liver function tests is unclear.
Lilford and colleagues conducted a prospective study conducted in 11 primary care practices, enrolling 1290 individuals with abnormal liver function tests. A diagnosis was established in less than 5% of cases. Only 17 (1.3%) of individuals were diagnosed with a condition requiring specific treatment, of which the majority (13) had viral hepatitis.
In a study by Armstrong and colleagues  of 1,118 patients seen in primary care, NAFLD and alcohol related liver disease were the commonest cause of abnormal liver function tests (26.4% and 25.3% respectively). Auto-immune and inherited metabolic conditions accounted for only 1% each.
We reviewed clinical notes, imaging and test results for three hundred and thirty eight consecutive patients investigated for with abnormal liver function tests, who presented to a large tertiary care hospital over a one-year period. We found alcoholic liver disease (22%) to be the commonest underlying diagnosis. A thorough history and ultrasound had the highest diagnostic yield, followed by testing for chronic viral hepatitis, which reached a diagnosis in 11% of patients. The cost per diagnosis varied substantially between tests (Table 1). The yield of screening for metabolic and auto-immune causes of liver disease was minimal.
Unselected diagnostic testing places a large financial burden on the NHS often for limited diagnostic yield. Further prospective studies comparing different diagnostic strategies for patients with abnormal liver function tests are urgently needed in order to inform clinical practice.
1 Sattar N, Forrest E, Preiss D. Non-alcoholic fatty liver disease. BMJ 2014;347:g4596–g4596. doi:10.1136/bmj.g4596
2 Lilford RJ, Bentham L, Girling A, et al. Birmingham and Lambeth Liver Evaluation Testing Strategies (BALLETS): a prospective cohort study. Health Technol Assess Winch Engl 2013;17:i–xiv, 1–307. doi:10.3310/hta17280
3 Armstrong MJ, Houlihan DD, Bentham L, et al. Presence and severity of non-alcoholic fatty liver disease in a large prospective primary care cohort. J Hepatol 2012;56:234–40. doi:10.1016/j.jhep.2011.03.020
4 Marks M. Routine test batteries for cognitive impairment in older people may not be cost effective. BMJ 2011;343:d6330.
Competing interests: No competing interests