Kim, Katherine Callaway
(2024)
Medication Utilization, Clinical, and Prescriber Behavior Impacts of Drug Shortages on Patients with Hypertension: Analysis of the 2018-2019 Angiotensin-II-Receptor Blocker(ARB) Recalls and Drug Shortages.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Drug recalls protect the public from potentially harmful products. However, recalls can result in drug shortages if insufficient infrastructure exists to compensate for recalled supply. Shortages impact how pharmacies dispense a drug and can influence patient care when prescribers must use alternatives.
Global shortages occurred in 2018-2019 when FDA recalled three angiotensin-receptor-II-blockers (ARBs) – valsartan, irbesartan, losartan - due to ingredient impurities. ARBs are recommended treatments for hypertension, heart failure, and chronic kidney disease.
This dissertation used national data to evaluate the impact of the ARB shortages on patient use and outcomes. Our difference-in-differences approach compared changes in outcomes for baseline users of the recalled ARBs versus changes among users of similar comparison drugs which did not experience shortages.
Aim 1 used all-payer claims from IQVIA to evaluate changes in anti-hypertension medications and drug spending post-ARB-shortages. Many ARB users transitioned to alternatives within 90 days. There were no observable changes in insurer and out-of-pocket drug spending. Fewer switches among those enrolled in Medicaid fee-for-service highlighted potential disparities in therapeutic substitution for groups who may experience greater difficulty accessing care.
Aim 2 used commercial claims and electronic-health-record data from Optum to evaluate changes in adherence, blood pressure and healthcare use post-ARB-shortages. Like Aim 1, switches to alternatives increased within 90 days. There were no changes in blood pressure, nor ambulatory care use. Delayed increases in medication gaps and cardiovascular-related hospitalizations may reveal clinical harm for some patients.
Therapeutic switches require a new prescription. In Aim 3, we used IQVIA data and a mixed interrupted time series approach to evaluate changes in provider-level prescribing post-ARB-shortages. Most prescribers substituted away from valsartan and to other ARBs. We did not observe spillovers to other anti-hypertensive classes. Results were consistent across prescriber characteristics.
Overall, our findings suggest that availability of alternatives during the ARB shortages may have mitigated gaps in access and subsequent harm. As policymakers consider solutions to shortages, increased availability for generic drugs of public health importance – as well as mitigation of barriers to therapeutic substitution - could increase resiliency and ensure consistent access for everyone.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
| Creators | Email | Pitt Username | ORCID  |
|---|
| Kim, Katherine Callaway | KAC377@pitt.edu | KAC377 | |
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| ETD Committee: |
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| Date: |
18 December 2024 |
| Date Type: |
Publication |
| Defense Date: |
22 October 2024 |
| Approval Date: |
18 December 2024 |
| Submission Date: |
24 October 2024 |
| Access Restriction: |
1 year -- Restrict access to University of Pittsburgh for a period of 1 year. |
| Number of Pages: |
329 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
School of Public Health > Health Policy & Management |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
Drug shortages; hypertension; drug recalls; pharmaceutical policy |
| Date Deposited: |
18 Dec 2024 20:06 |
| Last Modified: |
18 Dec 2024 20:06 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/47038 |
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