Emerging lessons from the drug effectiveness review project.

The Drug Effectiveness Review Project (DERP) is an alliance of fifteen states and two private organizations, which have pooled resources to synthesize and judge clinical evidence for drug-class reviews. The experience shines a bright light on challenges involved in implementing an evidence-based medicine process to inform drug formulary decisions: When should evidence reviewers accept surrogate markers and assume therapeutic class effects? How open and participatory should review procedures be? Should reviewers consider cost-effectiveness information? What is the appropriate role of the public sector in judging evidence? The DERP illustrates that attempts to undertake evidence-based reviews, apart from the methods themselves, which continue to evolve, involve questions of organization, process, and leadership.