For new stuff, FDA performs a holistic cost/benefit analysis. In this case, they might weigh: * How many new cases are caught by expanding access to specialist

For new stuff, FDA performs a holistic cost/benefit analysis. In this case, they might weigh: * How many new cases are caught by expanding access to specialist tools * What fail safes exist in current course of care — how does a false negative result in a worse outcome for a patient than if they had had no diagnostic at all * etc. The summary of their decision is public record, but not the detailed analysis.