(#39) Medication Adherence Following Pharmacogenomic Testing in Insurance Claims Data From Patients With Major Depressive Disorder

Abstract: Approximately 50% of patients with major depressive disorder (MDD) discontinue their antidepressant medication within 6 months, increasing risk of relapse. Pharmacogenomic testing (PGx) may improve adherence to medications by informing treatment based on gene-drug interactions. Here, we assessed medication adherence and discontinuation in patients with MDD who received a weighted multi-gene PGx test between 5 January 2015 and 30 September 2021 and had a psychiatric medication switch. PGx results from adult patients with MDD were de-identified and linked with de-identified administrative claims data from Optum Labs Data Warehouse. The PGx report organized psychiatric medications into three categories: no gene-drug interactions (congruent), moderate gene-drug interactions (congruent) and significant gene-drug interactions (incongruent). Using claims data, patients were assigned to the following groups based on medication congruency 90 days pre- and post-PGx testing: incongruent-to-congruent, congruent-to-incongruent, and no-change-in-congruency. Medication adherence (measured using proportion of days covered [PDC]) and discontinuation (a ≥45-day gap in medication fills) were assessed using pharmacy fill data during the 180 days after medication switch. Among 6,224 patients with PGx testing (72.9% female, mean age 44.8 years, SD 18.3), those in the incongruent-to-congruent group had the highest adherence (mean PDC 0.65, SD 0.33), compared to the congruent-to-incongruent (mean PDC 0.58, SD 0.34) and no-change-in-congruency groups (mean PDC 0.61, SD 0.34) (p 0.05). The incongruent-to-congruent group also had the lowest discontinuation rate (46%) compared to the congruent-to-incongruent (50%) and no-change-in-congruency groups (55%) (p 0.05). These findings suggest that PGx-guided medication selection in MDD patients can help improve medication adherence and reduce discontinuation.

Short Description: Medication adherence and discontinuation data were analyzed for major depressive disorder (MDD) patients who had weighted multi-gene pharmacogenomic testing (PGx) and a psychiatric medication switch. Patients were grouped by medication congruency before and after PGx. Adherence and discontinuation were assessed during the 180 days following medication change. Patients in the incongruent-to-congruent group had the highest adherence and lowest discontinuation rate, compared to other groups, suggesting PGx can improve adherence and reduce discontinuation in MDD treatment.

Name of Sponsoring Organization(s): Myriad Genetics