Patient comprehension of preemptive pharmacogenomic results.

Background: Preemptive pharmacogenomic (PGx) testing is a candidate for broad implementation because of its potential to improve medication safety and outcomes. However, little is known about how patients may process preemptively generated PGx information.

Methods: We conducted a survey study in a cohort of 5,000 individuals receiving preemptive PGx testing in a primary care clinic in the USA. We assessed patients' perceived understanding of results and confidence in current prescription drugs and doses before and after they received PGx information.

Results: 4,624 individuals completed the pre-results survey (92.8% survey completion rate), and 3,408 (74.4% of pre-results survey completers) completed the post-results survey. Participants currently taking prescription medications were more likely to report inability to understand their PGx results. Additionally, participants' confidence in their current prescription drugs and drug doses declined following receipt of PGx results, and this decline was associated with number of prescriptions and perceived understanding of PGx results. Health literacy and educational attainment were not associated with reduced confidence.

Conclusion: As preemptive PGx testing is considered for implementation in primary care settings, care must be taken to support patients with preexisting prescriptions to ensure adequate understanding of the immediate relevancy and actionability of PGx results in their healthcare.