Canadian Medication Cost Savings Associated with Combinatorial Pharmacogenomic Guidance for Psychiatric Medications

Abstract

Objective

To estimate Canadian pharmacy cost savings associated with psychiatric medication prescribing that is guided by combinatorial pharmacogenomic testing in patients switching or augmenting their psychiatric medication.

Methods

Pharmacy claims data from a United States (US) pharmacy benefit manager were analyzed for 1662 patients who recently augmented or switched to a different antidepressant or antipsychotic medication and underwent combinatorial pharmacogenomic testing. Costs of prescription medications were translated to the Canadian healthcare system by matching drug names and doses using the Ontario Drug Benefit Formulary. One-year costs (2017 CAD) were compared between patients whose clinician prescribed antidepressants or antipsychotics that were consistent (congruent) or inconsistent (incongruent) with the combinatorial pharmacogenomic test recommendations.

Results

Patients whose psychiatric medication treatment was congruent with the combinatorial pharmacogenomic test report saved $1061 CAD per member per year (PMPY) on prescription medication costs relative to patients whose medications were incongruent with their test report (p<0.0001). For patients ages <65 and ≥65, prescription medication costs were $979 and $1178 CAD PMPY lower, respectively, for patients who followed the report recommendations (p=0.0004 and p=0.13). Prescription drug fills from the US pharmacy claims were concordant with the Canadian Formulary; 62% of fills matched at both the drug name and dose strength, 81% matched at drug name, and >99% matched at the therapeutic chapter.

Conclusions

Antidepressant and antipsychotic prescribing that was congruent with combinatorial pharmacogenomic test guidance was associated with significant cost savings on Canadian prescription medications according to the Ontario Drug Benefit Formulary.

Keywords:

• pharmacogenomics
• genetic test
• genesight
• psychiatry
• mental health
• prescription
• pharmacy spend

Acknowledgements

The authors thank all study participants and Danielle Fanslow, PhD, for her assistance with manuscript preparation.

Data Availability

This study included a secondary analysis of previously published data. Please refer to Winner et al 2015 for information on data access.

Author Contributions

LC Brown, J Li, and BM Dechairo contributed to the design and implementation of the study. JA Tanner, LC Brown, K Yu, J Li, and BM Dechairo contributed to the analysis and interpretation of the data, writing and revising the manuscript, final approval of the manuscript for publication, and are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Disclosure

JA Tanner was employed by Assurex Health Ltd. at the time of this study. LC Brown, K Yu, and J Li were employed by Assurex Health, Inc., now Myriad Neuroscience, at the time of this study and received stock as part of their compensation. BM Dechairo was employed by Myriad Genetics, Inc. at the time of this study and received stock as part of his compensation. The authors report no other conflicts of interest in this work.

Additional information

Funding

This study was fully funded by Assurex Health, Inc. Funding during manuscript preparation was supported by Assurex Health, Inc. and a Mitacs Elevate Postdoctoral Fellowship (JAT).