Table 1.

Common features of reactive versus preemptive pharmacogenomic testing

Feature	Reactive pharmacogenomic testing	Preemptive pharmacogenomic testing
Timing of ordering	Ordered as drug therapy is initiated or being contemplated	Ordered independently of medication use
Turnaround time	Often ~5–7 business days; can be a point-of-care test (only available for a limited set of genes; use is not widespread)	Test result already available in the electronic health record at the time of prescribing; results can be reused as other medications are prescribed
Prescriber knowledge about pharmacogenomics	Requires knowledge about which test to order	Clinical decision support alerts prompt prescriber for action
Cost	Routinely found to be cost effective or cost saving, but expensive relative to the potential benefit of one therapeutic decision	Approximately equivalent to the cost of two single-gene tests, and provides cost savings over years with continued use of genetic information for medication use
General testing platform used	Often single gene (one pharmacogenomic test result)	Often array based (multiple pharmacogenomic test results)