Assessing the cost-effectiveness of prognostic biomarkers: a case study in prioritising patients waiting for coronary artery surgery

Abstract

In a recent study the cost-effectiveness of using information from circulating biomarkers to inform the prioritisation process of patients with stable angina awaiting coronary artery bypass graft surgery (CABG) was investigated.  A decision-analytic model was developed to compare four prioritisation strategies without biomarkers (no formal prioritisation, two urgency scores, and a risk score) and three strategies based on a risk score using biomarkers (routinely assessed estimated glomerular filtration rate (eGFR)), novel (C-reactive protein (CRP)) or both).  The order in which to perform CABG in a cohort of patients was determined by each prioritisation strategy, and mean lifetime costs and quality-adjusted life years (QALYs) compared. Using a cost-effectiveness threshold of 20,000 - 30,000 per additional QALY, a prioritisation strategy using a risk score with eGFR was the most cost effective strategy (cost per additional QALY was below 410 compared with Ontario urgency score). The impact on population health of implementing this strategy was 800 quality-adjusted life years per 100,000 patients at an additional cost of 245,000 to the National Health Service.

The prioritisation strategy using a risk score with CRP was associated with lower QALYs and higher costs compared with a risk score using eGFR.In this presentation the study is presented.

In this presentation the methods and results of the study will be presented with a focus on some of the methodological challenges associated with evaluating the cost-effectiveness of measuring biomarkers.  The challenges include defining the decision problem and a relevant framework for evaluation, development of statistical risk equations and incorporation of biomarker information into these, and the development and analysis of the actual decision model.