ECONOMIC EVALUATION OF A COMMUNITY BASED DIAGNOSTIC PATHWAY TO STRATIFY ADULTS AT RISK OF ALCOHOLIC LIVER DISEASE
Current diagnostic algorithms for investigating alcoholic liver disease (ALD) are based in secondary care which is associated with considerable costs and late diagnosis. We investigated the cost-effectiveness from an NHS England perspective of a community-based innovative diagnostic pathway (IDP) which stratifies patients at risk of ALD.
An economic evaluation was conducted to compare IDP, a pathway which identifies patients at risk of ALD in primary care and utilises transient elastography and a community hepatologist review to stratify patients, with standard care (SC), a referral to secondary care based on abnormal liver function tests. Brief alcohol intervention was assumed to be implemented in both arms.
Markov modelling of the natural history of ALD was combined with results of a prospective cross-sectional feasibility study (data on IDP and SC diagnostic accuracies). The following states were included in the model: no/mild liver disease (+/-), significant liver disease (+/-), compensated cirrhosis (+/-), split dependent on whether early disease is detected and treated (+) or not (-), decompensated cirrhosis, hepatocellular carcinoma, liver transplant and death. Starting age was 43, with 1-year cycle length and lifetime horizon, costs and utilities were discounted at 3.5%. Transition probability, utility and resource use data were taken from up-to-date UK sources. Due to poor data available for early disease progression and management, an expert panel of hepatologists was consulted to generate indicative estimates of probabilities and resource use.
An incremental cost-effectiveness ratio (ICER) was estimated, with extended one-way sensitivity analysis (OSA) to assess robustness of the results. Probabilistic sensitivity analysis (PSA) was performed, plotting an ICER-scatter-plane and a cost-effectiveness acceptability curve.
The analysis showed an ICER of £6,537 per extra quality adjusted life year (QALY), with QALY gain (0.45) and incremental cost (£2,973). OSA demonstrated ICER was robust and most sensitive to estimates on the effect of treatment on reducing the rate of fibrosis progression. PSA showed an ICER of £7,468/QALY (2.5%- 97.5% percentiles: 988-51,257), with QALY gain, 0.41 (0.00-0.88), and incremental cost, £3,137 (1,306-5,005), and demonstrated an 87% probability of cost-effectiveness at the UK willingness-to-pay threshold of £20,000/QALY.
IDP was cost-effective compared with SC, even in the presence of significant uncertainty around estimates. This suggests that IDP is likely to represent good value for money if implemented.