Time to review the role of surrogate endpoints in health policy: state of the art and the way forward

The efficacy of medicines, medical devices, and other health technologies should be proved in trials that assess final patient-relevant outcomes such as survival or morbidity. However, market access and coverage decisions are often based on surrogate endpoints, biomarkers, or intermediate endpoints, which aim to substitute and predict patient-relevant outcomes that are unavailable due to methodological, financial, or practical constraints. We provide a summary of the current use of surrogate endpoints in healthcare policy, discussing the case for and against their adoption and reviewing validation methods. We introduce a three-step framework for policy makers to handle surrogates, which involves establishing the level of evidence, assessing the strength of the association, and quantifying relations between surrogates and final outcomes. Although use of surrogates can be problematic, they can, when selected and validated appropriately, offer important opportunities for more efficient clinical trials and faster access to new health technologies that benefit patients and healthcare systems.