About

Inmaculada (Inma) Hernandez, Ph.D., is a Professor with tenure at the University of California, San Diego, within the Skaggs School of Pharmacy and Pharmaceutical Sciences. Her research program intersects health services research, pharmaceutical policy, and pharmacoepidemiology. Dr. Hernandez is a nationally recognized pharmaceutical policy scholar known for her significant contributions to transparency in drug pricing and reimbursement systems. She was the first to quantify the contributions of innovation versus inflation in rising drug prices and documented the disconnect between medication list prices and manufacturers’ net revenue, which involves confidential rebates. Her development of an algorithm to track cash flow across the drug supply chain has produced the first public estimates of confidential manufacturer discounts to pharmacy benefit managers for leading drug products. Dr. Hernandez has been recognized with numerous awards, including being listed on Forbes 30 under 30 in 2018 and receiving the Academy Health Alice S. Hersh Emerging Leader Award in 2021. She has testified before the Senate Finance Committee and her research has been cited in high-profile policy documents, including reports to Congress, CDC guidelines, FDA reports, and NIH requests for information. Her academic background includes a Ph.D. in Health Services Research and Policy from the University of Pittsburgh, an MS in Health Economics and Pharmacoeconomics from Pompeu i Fabra University in Spain, and an international equivalent PharmD from the University of Navarra in Spain.

Research topics

• Political Science
• Computer Science
• Library science
• Family medicine
• Medical education
• Medicine

Selected publications

• External Exposome Factors and Adverse Heart Failure Outcomes in the OneFlorida+ Network: Retrospective Cohort Study

  JMIR Formative Research · 2025-08-25

  articleOpen access

  Background: Heart failure (HF) readmission rates vary across geographic regions in the United States, yet the impact of external exposome factors, such as contextual-level social determinants of health (SDoH), on adverse HF outcomes is not well understood. Objective: This study aims to examine the association between external exposome factors and the risk of HF readmission and all-cause mortality using a data-driven approach. Methods: We conducted a retrospective cohort study using electronic health record (EHR) data from the OneFlorida+ Network, including patients hospitalized for HF (HHF) from 2016 to 2022. A total of 1308 external exposome factors, covering a wide range of SDoH (eg, economic stability, education, health care access, natural and built environments, and social context), were linked to patients' EHR data based on their county-level residential location. Patients were followed for 1 year after their first HHF to capture readmission and mortality events. We applied the least absolute shrinkage and selection operator regularization to preselect candidate variables, followed by a 2-phase external exposome-wide association study using mixed-effects logistic regression to identify key factors associated with the composite outcome of 1-year HF readmission and mortality. Results: Among 63,940 patients with HF (n=30,475, 48% women; mean age 65, SD 14 years), higher maximum temperature in May was significantly associated with increased risk of the composite outcome (adjusted odds ratio [aOR] 1.04, 95% CI 1.02-1.06; P<.001). Subgroup analyses showed consistent associations across age, sex, race, socioeconomic status, and rural or urban strata. Conclusions: Using a data-driven approach, we found that elevated maximum temperature in May (late spring) was significantly associated with HF readmission and mortality in Florida. Further investigations are warranted to uncover the intricate mechanisms through which extreme heat potentially influences HF outcomes.

  PublisherOA PDFDOI

• Projected Out-of-Pocket Savings of the Medicare Part D $2 Drug List Model

  JAMA · 2025-03-24

  articleOpen access1st authorCorresponding

  This study evaluates the amount of out-of-pocket cost savings Medicare Part D beneficiaries would have experienced if a proposed Medicare $2 drug list model had been in place in 2021.

  PublisherOA PDFDOI

• DRUG PRICING, EJECTION FRACTION, AND COST-EFFECTIVENESS OF PHARMACOLOGIC TREATMENTS FOR HEART FAILURE: A SYSTEMATIC REVIEW

  Journal of the American College of Cardiology · 2025-03-29

  reviewOpen access
  PublisherDOI

• Overpayment for Generic Drugs Under Medicare Part D

  JAMA Health Forum · 2025-02-28 · 1 citations

  articleOpen access1st authorCorresponding

  This cross-sectional study evaluates whether certain pharmacy benefit manager practices result in increased out-of-pocket costs for Medicare Part D beneficiaries.

  PublisherOA PDFDOI

• Vulnerability Index Approach to Identify Pharmacy Deserts and Keystone Pharmacies

  JAMA Network Open · 2025-03-13 · 13 citations

  articleOpen accessSenior author

  Importance: Community pharmacies are crucial for public health, providing essential services such as medication dispensing, vaccinations, and point-of-care testing. Addressing disparities in pharmacy access, particularly in underserved rural and low-income areas, is critical for health equity. Objective: To identify areas in the US at risk of becoming pharmacy deserts through the development of a novel pharmacy vulnerability index. Design, Setting, and Participants: This population-based cross-sectional study in the contiguous 48 states performed geographic information systems analysis of pharmacy data from the National Council for Prescription Drug Programs (NCPDP) dataQ. Participants included all open-door pharmacies (community or retail pharmacies open to the general public without restrictions on who can access its services) in the US as of February 2024. Statistical analysis was performed from July to August 2024. Exposure: The primary exposure was travel time to pharmacies across the US. Main Outcomes and Measures: A pharmacy desert was defined as a census tract where the travel time to the nearest pharmacy exceeds the supermarket access time for that region and urbanicity level. Building on this definition, a pharmacy vulnerability index was developed, which indicates the number of pharmacies that would need to close for a census tract to become a pharmacy desert. Tracts with a pharmacy vulnerability index of 1, depending solely on a single pharmacy for access, were identified as at risk of becoming deserts. Subpopulation totals and percentages living in pharmacy deserts or relying on keystone pharmacies were computed, and then stratified by urbanicity and race. Results: Among 321.3 million individuals (39.7 million [12.3%] Black, 59.0 million [18.2%] Hispanic, 195.0 million [60.3%] White) in the contiguous US, 57.1 million (17.7%) were identified as living in pharmacy deserts, with 28.9 million (8.9%) additionally relying on a single pharmacy for access. Small rural areas were particularly affected, with a higher dependency on single pharmacies (4.1 million individuals [14.3%]). Conclusions and Relevance: In this cross-sectional study of pharmacy access in the US, significant disparities in pharmacy access were identified, especially pronounced in small rural areas. Targeted policy interventions, such as incremental reimbursement rates or other monetary incentives, are needed to ensure the financial sustainability of pharmacies that serve as the sole source of pharmacy services in at-risk areas.

  PublisherOA PDFDOI

• HPR36 Estimated Impact of the Inflation Reduction Act on Out-of-Pocket Spend Among Medicare Part D Beneficiaries with Cancer

  Value in Health · 2025-07-01

  articleSenior author
  PublisherDOI

• Abstract 4364346: Risk of Hospitalization in Patients with Heart Failure Exposed to Extreme Heat and Poor Air Quality in the Western United States

  Circulation · 2025-11-03

  article

  Introduction: Patients with underlying cardiovascular (CV) disease are vulnerable to adverse health events related to extreme weather. Limited data exist in those with heart failure (HF). In the western U.S., where heat waves and wildfire exposure are common, understanding the impact of heat on HF–related outcomes is critical for prevention and clinical management. Research Question/Hypothesis: We examined the risk of hospitalizations and emergency room (ER) visits associated with short-term exposure to extreme heat and poor air quality in HF patients stratified by HF type. Methods: Using 2021 Medicare data, we identified patients with HF before January 1, 2021, residing in 11 western U.S. states (Arizona, California, Colorado, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington, and Wyoming). The primary outcomes included all-cause, CV, and HF-related hospitalizations and ER visits. A case-crossover design was used, with case days defined as the event date and control days matched by day of the week within the same month. Patients were stratified based on HF type and identified on inpatient or outpatient diagnoses prior to the case day. Conditional logistic regression was applied to estimate odds ratios (ORs) for outcomes associated with extreme heat exposure, defined as daily maximum temperature above the 85th percentile of the local decadal average, adjusting for airborne particulate matter (PM 2.5. ) levels and public holidays. Results: We identified 43,447 HF patients (mean age 73 ±16 years) of whom 9,676 had HF with reduced ejection fraction (HFrEF) and 13,093 HF with preserved ejection fraction (HFpEF). Only extreme heat exposure was associated with a 6% increased odds for all-cause hospitalization (OR 1.06; 95% CI: 1.02,1.10); 10% increase in all-cause ER visits (OR:1.10; 95% CI 1.06-1.15); and 8% increase CV-related ER visits (OR 1.08; 95% CI: 1.00–1.17). These effects were demonstrated primarily in HFpEF and not HFrEF (Table). Conclusion: Short-term extreme heat exposure but not poor air quality was associated with an increased risk of hospitalization and ER visits in HF patients residing in the Western US, especially in those with HFpEF. This heightened vulnerability may be due to impaired thermoregulation and reduced cardiovascular adaptability in those with HFpEF

  PublisherDOI

• 2025 AHA/ACC Statement on Cost/Value Methodology in Clinical Practice Guidelines (Update From 2014 Statement): A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

  Circulation · 2025-09-25 · 10 citations

  review

  AIM: The "2025 AHA/ACC Statement on Cost/Value Methodology in Clinical Practice Guidelines (Update From 2014 Statement)" describes a systematic approach for consistent implementation of "economic value statements" across ACC/AHA guidelines. It updates the cost-effectiveness threshold and proposes a new level of certainty framework that summarizes the strength of the available evidence. Additionally, it describes how cost-effectiveness analyses (CEAs) can help advance equity in population cardiovascular health. METHODS: A focused literature search was conducted from January 9, 2024, to February 2, 2024, encompassing English-language publications related to CEA methodology in PubMed, EMBASE, and the Cochrane Library, with publication dates ranging from 1973 to the present. Additional relevant studies published during the writing process (through June 25, 2024) were also considered by the writing committee. STRUCTURE: This Cost/Value Methodology Statement updates prior guidance regarding the incorporation of evidence from published CEAs into clinical guidelines. It provides guidance for identifying and synthesizing relevant high-quality evidence, developing economic value statements, and communicating level of certainty in such statements. It defines the US cost-effectiveness threshold as $120 000 per quality-adjusted life year gained, highlights special considerations related to cardiovascular drugs and devices, emphasizes health equity considerations when interpreting CEAs, and defines a reference case for future CEAs.

  PublisherDOI

• Use of Potentially Nephrotoxic Drugs in Type 2 Diabetes Patients on <scp>SGLT2i</scp>: A Trajectories Analysis

  Pharmacoepidemiology and Drug Safety · 2025-01-22 · 1 citations

  articleOpen accessSenior author

  PURPOSE: To characterize trajectories of nephrotoxic potential (NxP) drug use among older adults with Type 2 Diabetes (T2D) treated with SGLT2is and identify associated patient characteristics. METHODS: Using 2012-2019 Medicare data, we selected patients with T2D who filled at least one prescription for SGLT2is. Index date was the date of the first SGLT2i prescription filled. We quantified the number of drugs with NxP used every month during the first 12 months following the index date. The monthly counts of drugs with NxP were incorporated into the group-based trajectory model to identify groups with similar drug use patterns. Finally, we performed a multinomial logistic regression model to examine the association between patient characteristics and group membership. RESULTS: The study cohort comprised 8811 Medicare beneficiaries with T2D who initiated SGLT2i during the study period with the mean age 67.5 ± 10.6 years. We identified 3 trajectories NxP drug use: no (n = 2142, 24%), low (n = 4752, 54%) and high (n = 1917, 22%) use of drugs with NxP, with patients falling into these categories based on the number of drugs with NxP they used over the time: no drugs, one drug, or two or more drugs. Age, gender, low-income subsidy eligibility and clinical characteristics were associated with group membership. CONCLUSIONS: We successfully identified three trajectory groups, with a substantial proportion of patients showing low use of drugs with NxP. Both social and clinical factors were associated with the use of NxP drugs.

  PublisherOA PDFDOI

• Geographic access to community pharmacies based on walking, driving, and public transportation in the 10 most populated U.S. areas

  Journal of the American Pharmacists Association · 2025-07-18

  articleSenior author
  PublisherDOI

Recent grants

• Patient and System-Level Determinants of Oral Anticoagulation Use in Atrial Fibrillation

  NIH · $798k · 2018–2023

Frequent coauthors

• Laura E. Happe

  University of Florida

  179 shared

• Robert Navarro

  179 shared

• Patty Taddei-Allen

  179 shared

• Prabashni Reddy

  Mass General Brigham

  179 shared

• M. L. Hunter

  Maine Department of Marine Resources

  178 shared

• Rolin L. Wade

  IQVIA (United States)

  178 shared

• Karen L. Rascati

  The University of Texas at Austin

  178 shared

• Susan A. Cantrell

  178 shared

Education

• PhD in Health Services Research and Policy

  University of Pittsburgh

  2016

• MS in Health Economics and Pharmacoeconomics

  Universitat Pompeu Fabra

  2013

Awards & honors

• International Society for Pharmacoeconomics and Outcomes Res…
• PhRMA Foundation Challenge Award for Addressing Unanswered Q…
• National Academy of Medicine Fellow in Pharmacy (2022)
• Journal of Managed Care and Specialty Pharmacy Award for Exc…
• Alice S. Hersh Emerging Leader Award (2021)