What is the performance of biomarker-based scores in real-world clinical practice?
The performance of biomarker-based scores in real-world clinical practice (outside highly selected trial cohorts) has been disappointing, given that baseline (or near-baseline) determination of biomarkers to predict bleeding risks after many years is bedeviled by the changing clinical risk profile of patient's risks as well as modification of risk factors. Many of these risk scores have been derived from highly selected clinical trial cohorts (often anticoagulated), with the biomarkers measured at baseline (or within a few months of study entry) then end points determined many years later. Biomarkers are also expensive, and may be subject to laboratory variability, inter-assay differences, diurnal variation and may change in individual patients depending on how risk factors and drug treatments change over time. 