THE VALUE OF INFORMATION OF ADDITIONAL RESEARCH REGARDING BIRTH-COHORT SCREENING FOR HEPATITIS C

Purpose: Several published studies have estimated that a onetime hepatitis C virus (HCV) screening of patients born between 1945 and 1965 (birth-cohort screening) followed by standard therapy with an additional protease inhibitor is likely to be cost-effective at a willingness-to-pay (WTP) below $45,000 per incremental QALY gained.  The purpose of this paper is to estimate the expected value of parameter perfect information (EVPPI) for four key parameters in models of HCV birth-cohort screening followed by treatment; treatment effectiveness, treatment costs, utility losses from early disease states, and the speed of disease progression.

Method: We evaluated outcomes associated with a one-time antibody test of individuals born between 1945–1965 with 1 or more visits to a primary care provider annually, as compared to current risk-based screening.   We estimated cost-effectiveness from the healthcare perspective using a lifetime time-horizon and 3% discount rate.   To estimate EVPPI, we applied a published 1-step ‘shortcut algorithm’.  Our analyses primary outcomes were the per person and cumulative EVPPI and the distribution of opportunity costs.

Result: At a WTP of $42,000 per QALY gained, the cumulative EVPPI was $3.0 billion.  At $42,000 per QALY gained, 51.5% of simulations resulted in no opportunity costs, 14.8% with opportunity costs between $0 and $3 billion, and 34.5% with opportunity costs in excess of $3.0 billion.  The EVPPI was $112 million at a WTP of $75,000 per QALY gained with a 3.8% chance of any opportunity losses.  The EVPPI was $0 at $100,000 per QALY gained with no chance of opportunity costs.  QALY losses from chronic disease states and the costs of new therapies were more important sources of uncertainty than the effectiveness of new therapy or the speed of fibrosis progression.  

Conclusion: Additional research prior to the implementation birth-cohort screening is warranted at a WTP near the ICER of the baseline results, $42,000 per QALY gained.  As WTP increases, the rationale for such research and delay decreases.  At WTP values of $75,000 per QALY gained or higher, additional research is very unlikely to lead to a decision other than the implementation of birth-cohort screening.