Impact of a Mail-Based Intervention on Adherence to Direct Oral Anticoagulants Among Medicare and Medicaid Beneficiaries
by Ashley K. Golter, PharmD, Agata Siwak, PharmD, MSBA, Marnie K. Wickizer, PharmD, AE-C, CDCES, Robert Topp, PhD, RN
Abstract
Objective:
To determine the impact of mail-to-prescriber letters on adherence to direct oral anticoagulants (DOACs) among Medicare and Medicaid beneficiaries identified as nonadherent.
Methods:
This retrospective analysis included Medicare and Medicaid patients with a proportion of days covered (PDC) below 0.80 for DOACs between October 1, 2022, and September 30, 2023. The identified patients’ prescribers received mailings in October 2023 that included patient medication profiles with pharmacy claims records to illustrate adherence behavior. Adherence outcomes were assessed at 6 months post- intervention, along with the impact of gender, age, and health plan type/Low-Income Subsidy status on DOAC adherence.
Results:
There was a statistically significant improvement in PDC between the pre- and post-intervention periods (mean [SD] = 0.61 [0.16] vs. 0.81 [0.22], P < 0.001). Gap in therapy (GIT) days significantly decreased between pre- and post-intervention (mean [SD] = 51.5 [51.4] vs. 28.7 [34.7] days, P < 0.001). Compared to ages < 55 years, odds of adherence were 6.78 (P = 0.01) and 5.55 (P = 0.02) times higher among individuals aged 65-74 years and ≥ 75 years respectively. There was no significant association between gender or plan type with adherence.
Conclusion:
The mail-based intervention increased DOAC adherence and reduced therapy gaps, supporting its continued use in nonadherent patient populations. Adherence may be more likely among patients ≥ 65 years of age, indicating a potential area for tailored strategies or additional outreach processes for younger patients. Future studies investigating longer-term outcomes of this intervention would be beneficial.
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2025 November/December Table of Contents
Abstract
Objective:
To determine the impact of mail-to-prescriber letters on adherence to direct oral anticoagulants (DOACs) among Medicare and Medicaid beneficiaries identified as nonadherent.
Methods:
This retrospective analysis included Medicare and Medicaid patients with a proportion of days covered (PDC) below 0.80 for DOACs between October 1, 2022, and September 30, 2023. The identified patients’ prescribers received mailings in October 2023 that included patient medication profiles with pharmacy claims records to illustrate adherence behavior. Adherence outcomes were assessed at 6 months post- intervention, along with the impact of gender, age, and health plan type/Low-Income Subsidy status on DOAC adherence.
Results:
There was a statistically significant improvement in PDC between the pre- and post-intervention periods (mean [SD] = 0.61 [0.16] vs. 0.81 [0.22], P < 0.001). Gap in therapy (GIT) days significantly decreased between pre- and post-intervention (mean [SD] = 51.5 [51.4] vs. 28.7 [34.7] days, P < 0.001). Compared to ages < 55 years, odds of adherence were 6.78 (P = 0.01) and 5.55 (P = 0.02) times higher among individuals aged 65-74 years and ≥ 75 years respectively. There was no significant association between gender or plan type with adherence.
Conclusion:
The mail-based intervention increased DOAC adherence and reduced therapy gaps, supporting its continued use in nonadherent patient populations. Adherence may be more likely among patients ≥ 65 years of age, indicating a potential area for tailored strategies or additional outreach processes for younger patients. Future studies investigating longer-term outcomes of this intervention would be beneficial.
Download PDF
2025 November/December Table of Contents