Sean Hennessy, PharmD, PhD

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Professor of Epidemiology in Biostatistics and Epidemiology
Department: Biostatistics and Epidemiology

Contact information
University of Pennsylvania
423 Guardian Drive
803 Blockley Hall
Philadelphia, PA 19104-6021
Office: 215-898-9112
Fax: 215-573-5315
BS (Pharmacy)
Philadelphia College of Pharmacy and Science, 1989.
PharmD (Clinical Pharmacy)
Philadelphia College of Pharmacy and Science, 1990.
MSCE (Clinical Epidemiology)
University of Pennsylvania School of Medicine, 1996.
PhD (Epidemiology with Biostatistics minor)
University of Pennsylvania, 2002.
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Description of Research Expertise

Sean Hennessy leads Penn's Division of Epidemiology and its Center for Real-world Effectiveness and Safety of Therapeutics (CREST). His research evaluates the real-world effectiveness and safety of prescription drugs using healthcare data. He and his colleagues identified a survival benefit of potassium supplements in users of loop diuretics, and found that this survival benefit increases with hotter outdoor temperatures. They also found that the survival benefit of statin drugs increases with hotter outdoor temperatures. His research program studies serious health consequences of drug-drug interactions involving high-risk drugs including anticoagulants, treatments for diabetes, and medications used for opioid use disorder. His team also evaluated an early approach, known as drug utilization review, to using health insurance data to improve prescribing, finding it ineffective despite its federal mandate. This contributed to the omission of a requirement for drug utilization review programs in Medicare Part D. He co-led a pair of studies that demonstrated the effectiveness and safety of the SA14-14-2 vaccine for Japanese encephalitis (JE), which subsequently led to the immunization of millions of children per year in populous countries including Cambodia, India, Malaysia, Nepal, Sri Lanka, and Thailand. Use of that vaccine has been credited with reducing the worldwide incidence of JE. He and his colleagues also developed the instrumented difference-in-differences research design for studying the effects of exposures with marked time trends. He was the senior author of one of two citizen petitions to the US Food and Drug Administration that led to re-labeling of metformin, the best-proven therapy for type 2 diabetes, to permit its use in the millions of persons with both diabetes and mild-to-moderate renal insufficiency. He has served as chair of NIH's Health Services and Organizational Delivery study section and its Health Services Quality and Effectiveness study section.

Description of Other Expertise

Dr. Hennessy has served as scientific program chair and president of the International Society for Pharmacoepidemiology, regional editor for the Americas of the journal Pharmacoepidemiology and Drug Safety, as a member of FDA’s Drug Safety and Risk Management Advisory Committee, and on the board of directors of the American Society for Clinical Pharmacology and Therapeutics. He is a co-editor of the books Pharmacoepidemiology, 6th edition and Textbook of Pharmacoepidemiology, 2nd edition.

Additional Positions:
Director, Center for Pharmacoepidemiology Research & Training
Interim Director, Division of Epidemiology, Department of Biostatistics, Epidemiology and Informatics
Senior Scholar, Center for Clinical Epidemiology and Biostatistics
Senior Fellow, Leonard Davis Institute of Health Economics
Fellow, Institute on Aging
Member, Pharmacy and Therapeutics Committee, University of Pennsylvania Health System
Special Government Employee, US FDA
Member, Council for International Organizations of Medical Sciences (CIOMS) Work Group XIII on Real-World Data & Evidence in Regulatory Decision Making

Courses Led:
EPI 666: Pharmacoepidemiology Research Methods

1998 Stanley A. Edlavitch Award for Best Abstract Submitted by a Student, International Society for Pharmacoepidemiology
2002 Saul Winegrad Award for Outstanding Dissertation in Epidemiology and Biostatistics, University of Pennsylvania
2005 Young Alumnus Award, University of the Sciences in Philadelphia
2008 Leon I Goldberg Young Investigator Award, American Society for Clinical Pharmacology & Therapeutics
2013 Samuel Martin Health Evaluation Sciences Research Award, University of Pennsylvania Perelman School of Medicine
2014 Julius W. Sturmer Memorial Lecture Award, Alpha Tau Chapter of the Rho Chi Society, Philadelphia College of Pharmacy, University of the Sciences
2015 Elected Member, National Academy of Medicine

Selected Publications

Brumberg K, Ellis DE, Small DS, Hennessy S, Rosenbaum PR: Using natural strata when examining unmeasured biases in an observational study of neurological side effects of antibiotics. Journal of the Royal Statistical Society: Series C 2023 (https://doi.org/10.1093/jrsssc/qlad010).

Shah M, Mamtani R, Marmarelis ME, Hennessy S: Chemoimmunotherapy versus immunotherapy for first line treatment of advanced non-small cell lung 2 cancer with a PD-L1 expression >=50% or >=90%. Clinical Lung Cancer 2023 (https://doi.org/10.1016/j.cllc.2023.02.007).

Roy S, Ye T, Ertefaie A, Vo T-T, Flory J, Hennessy S, Small D: Group sequential testing under instrumented difference-in-differences approach. Statistics in Medicine 2023 (https://doi.org/10.1002/sim.9836).

Shu D, Han P, Hennessy S, Miano TA: Robust causal inference of drug-drug interactions. Statistics in Medicine 2023 (https://doi.org/10.1002/sim.9653).

Dhopeshwarkar N, Yang W, Hennessy S, Rhodes JM, Cuker A, Leonard CE: Bleeding with concomitant ibrutinib and oral anticoagulant therapy: a population-based cohort study. American Journal of Hematology 2023 (forthcoming).

Abraham DS, Pham Nguyen TP, Blank LJ, Thibault D, Gray SL, Hennessy S, Leonard CE, Weintraub D, Willis AW : Channeling of new neuropsychiatric drugs—-Impact on safety and effectiveness studies. Neurotherapeutics 2023 (epub ahead of print).

Pham Nguyen TP, Gray SL, Newcomb CW, Liu Q, Hamedani AG, Weintraub D, Hennessy S, Willis AW.: Potentially inappropriate medications in older adults with Parkinson disease before and after hospitalization for injury. Parkinsonism & Related Disorders 2023 (doi.org/10.1016/j.parkreldis.2023.105793).

Abraham AS, Nguyen TPP, Newcomb CW, Gray SL, Hennessy S, Leonard CE, Liu Q, Weintraub D, Willis AW: Comparative safety of antimuscarinics versus mirabegron for overactive bladder in Parkinson disease. Parkinsonism and Related Disorders 2023 (DOI: 10.1016/j.parkreldis.2023.105822).

Dhopeshwarkar N, Yang W, Hennessy S, Rhodes JM, Cuker A, Leonard CE: Combining SuperLearner with high-dimensional propensity score to improve confounding adjustment: A real-world application in chronic lymphocytic leukemia. Pharmacoepidemiology and Drug Safety 2023 (DOI: 10.1002/pds.5678 ).

Golder S, Medaglio D, O'Connor K, Hennessy S, Gross R, Gonzalez Hernandez G: Reasons for discontinuation or change of selective serotonin reuptake inhibitors in online drug reviews. JAMA Network Open 6: e2323746, 2023.

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Last updated: 09/05/2023
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