An economic analysis presented at the 2017 Neuroscience Educational Institute (NEI) Congress in Colorado Springs, Colorado, showed that pharmacogenomic testing in patients with specific psychiatric disorders can reduce the utilization of benzodiazepines.
The prospective study was conducted in individuals with either generalized anxiety disorder (GAD, n = 318) or major depressive disorder (MDD, n = 459)—eligible patients included those who had augmented or changed their antidepressant or antipsychotic medications within the previous 90 days. Combinatorial pharmacogenomic testing was offered following a medication switch or augmentation; the authors classified the medications into 1 of 3 categories following the test results:
- Use as directed
- Moderate gene–drug interactions
- Significant gene–drug interactions
Pharmacy claims data were assessed for a year post testing and cost savings were calculated per member per year (PMPY), based on whether the test was used in decision making. For 660 patients who had been prescribed at least 1 benzodiazepine, the cost of benzodiazepine utilization was analyzed for 6 months pretest and 6 months post test.
The analysis found that in both, the GAD group and the MDD group, PMPY cost savings were significant if the healthcare provider’s decisions were congruent with the results of the pharmacogenomic testing. The authors found that congruent prescribing yielded $6747 in PMPY medication savings in the GAD group, compared with incongruent prescribing; PMPY savings in the MDD cohort were $3738 with congruent prescribing.
When the authors drilled further into the savings observed in the claims data in the congruent group, they found the highest savings were with medications used to treat neurological and psychiatric disorders (GAD, $2700; MDD, $1332), followed by anti-neoplastic drugs (GAD, $2696; MDD, $1038). The lowest savings were observed with dermatology medications for the GAD group ($1) and vitamins for the MDD group ($5).
Physician prescribing of benzodiazepine changed significantly following pharmacogenomic testing, both with respect to drug counts and refills, the study found.
The authors credit the pharmacogenomic test, GeneSight, as a useful treatment decision support tool in GAD and MDD. Using the tool resulted in significant cost savings when providers made congruent decisions with the pharmacogenomic results, they conclude, adding that the reduction in benzodiazepine prescription in the congruent cohort could reduce the need for benzodiazepines.