BETHESDA, Maryland — The first day of the evidence-based reimbursement summit by the Cambridge Health Institute (CHI; Needham, Massachusetts) included an extensive focus on companion diagnostics (CDx) Hey, which by some accounts is a strange land for many payers. Usman Iqbal, senior medical affairs leader at AstraZeneca (London), reviewed the application of health economics for companion diagnostics, and he offered several recommendations, but he also characterized the current state of affairs for evaluating CDx as "very fragmented."