Earlier Detection And Treatment of Non-Alcoholic Fatty Liver Disease: An Economic Evaluation to Appraise An Innovative Diagnostic Pathway to Detect And Intervene Where There Are Known Risk Factors

Abstract

Objectives: The prevalence of liver disease is increasing and often remains undetected until the late stages. The study estimated cost-effectiveness of an innovative diagnostic pathway (IDP) targeting adults with risk factors of non-alcoholic fatty liver disease (NAFLD) from an NHS England perspective. Methods: Economic evaluation compared IDP (algorithm applied in a general practice to identify adults with risk factors for NAFLD, then stratifying disease severity using a Fibroscan to test liver stiffness, followed by hepatologist-led treatment appropriate to disease stage) with standard care (SC, hepatology referral due to abnormal LFTs). Probabilistic modelling of NAFLD progression was combined with the diagnostic accuracy of IDP and SC estimated from a feasibility study, incorporating fibrosis stages (no/mild disease, moderate liver disease, compensated cirrhosis) split into health states: 'identified' and 'unidentified' risk factor/disease. Advanced NAFLD states were: decompensated cirrhosis, hepato-cellular carcinoma, liver transplant and death. Transition probability, utility and resource use data were based on uptodate UK sources, or - if not possible - on expert panel responses to indicate early disease management and its estimated effectiveness. Lifetime Markov cohort modelling with starting age of 68, annual cycle, and costs and utilities discounted at 3.5%-rate, was applied. Cost-effectiveness planes and cost-effectiveness acceptability curves, based on 5000-sample Monte Carlo simulation, were constructed. Results: IDP yielded increased QALYs (95% CI) ( 0.24 (-0.18, 0.63)) and reduced costs (-£2661 (-10831, 7099), compared with SC, with 69.7%-probability of dominance, and 88.3%-probability of cost-effectiveness at £20000/QALY threshold. The results were associated with high levels of uncertainty due to the poor quality of data available for transition probabilities in early liver disease. Conclusions: Indicative economic evaluation showed that IDP may be cost-effective, compared with standard care. Due to large uncertainty of model input parameters and no data around progression and management of early liver disease, further studies on IDP implementation are needed.