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Sean Hennessy, PharmD, PhD
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Professor of Epidemiology in Biostatistics and Epidemiology
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Senior Fellow, Leonard Davis Institute of Health Economics, University of Pennsylvania
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Fellow, Institute on Aging, University of Pennsylvania
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Senior Scholar, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Perelman School of Medicine
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Founding Director, Center for Real-World Effectiveness and Safety of Therapeutics, University of Pennsylvania Perelman School of Medicine
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Member, Abramson Cancer Center, University of Pennsylvania Perelman School of Medicine
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Department: Biostatistics and Epidemiology
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Graduate Group Affiliations
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Contact information
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University of Pennsylvania
23 3600 Civic Center Boulevard
2f 4W-105C
Philadelphia, PA 19104-3413
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23 3600 Civic Center Boulevard
2f 4W-105C
Philadelphia, PA 19104-3413
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Office: 215-898-9112
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Email:
hennessy@upenn.edu
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hennessy@upenn.edu
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Publications
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Links
106 Search PubMed for articles
53 Twitter
76 CCEB Faculty Page
8b Center for Pharmacoepidemiology Research and Training (CPeRT)
b4 NCBI Bibliography
a9 Department of Biostatistics, Epidemiology & Informatics faculty page
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106 Search PubMed for articles
53 Twitter
76 CCEB Faculty Page
8b Center for Pharmacoepidemiology Research and Training (CPeRT)
b4 NCBI Bibliography
a9 Department of Biostatistics, Epidemiology & Informatics faculty page
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Education:
21 7 BS 15 (Pharmacy) c
45 Philadelphia College of Pharmacy and Science, 1989.
21 b PharmD 1e (Clinical Pharmacy) c
45 Philadelphia College of Pharmacy and Science, 1990.
21 9 MSCE 22 (Clinical Epidemiology) c
46 University of Pennsylvania School of Medicine, 1996.
21 8 PhD 32 (Epidemiology with Biostatistics minor) c
33 University of Pennsylvania, 2002.
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Permanent link21 7 BS 15 (Pharmacy) c
45 Philadelphia College of Pharmacy and Science, 1989.
21 b PharmD 1e (Clinical Pharmacy) c
45 Philadelphia College of Pharmacy and Science, 1990.
21 9 MSCE 22 (Clinical Epidemiology) c
46 University of Pennsylvania School of Medicine, 1996.
21 8 PhD 32 (Epidemiology with Biostatistics minor) c
33 University of Pennsylvania, 2002.
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1d Additional Positions:
50 Director, Center for Real-World Effectiveness and Safety of Therapeutics
2a Director, Division of Epidemiology
4a Senior Scholar, Center for Clinical Epidemiology and Biostatistics
42 Senior Fellow, Leonard Davis Institute of Health Economics
22 Fellow, Institute on Aging
5d Member, Pharmacy and Therapeutics Committee, University of Pennsylvania Health System
2b Special Government Employee, US FDA
9f Member, Council for International Organizations of Medical Sciences (CIOMS) Work Group XIII on Real-World Data & Evidence in Regulatory Decision Making
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15 Courses Led:
34 EPID 7050 Grant Writing & Scientific Writing
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f Honors:
80 1998 Stanley A. Edlavitch Award for Best Abstract Submitted by a Student, International Society for Pharmacoepidemiology
7b 2002 Saul Winegrad Award for Outstanding Dissertation in Epidemiology and Biostatistics, University of Pennsylvania
4c 2005 Young Alumnus Award, University of the Sciences in Philadelphia
70 2008 Leon I Goldberg Young Investigator Award, American Society for Clinical Pharmacology & Therapeutics
7c 2013 Samuel Martin Health Evaluation Sciences Research Award, University of Pennsylvania Perelman School of Medicine
9d 2014 Julius W. Sturmer Memorial Lecture Award, Alpha Tau Chapter of the Rho Chi Society, Philadelphia College of Pharmacy, University of the Sciences
39 2015 Elected Member, National Academy of Medicine
82 2024 William B. Abrams Award in Geriatric Clinical Pharmacology, American Society for Clinical Pharmacology & Therapeutics
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Description of Research Expertise
809 Sean Hennessy leads Penn's 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. 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, and is widely cited in clinical compendia of drug-drug interactions. 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 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.6e
Description of Other Expertise
1f0 Dr. Hennessy has served as scientific program chair and president of the International Society for Pharmacoepidemiology, regional editor for 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, 3rd edition.8
1d Additional Positions:
50 Director, Center for Real-World Effectiveness and Safety of Therapeutics
2a Director, Division of Epidemiology
4a Senior Scholar, Center for Clinical Epidemiology and Biostatistics
42 Senior Fellow, Leonard Davis Institute of Health Economics
22 Fellow, Institute on Aging
5d Member, Pharmacy and Therapeutics Committee, University of Pennsylvania Health System
2b Special Government Employee, US FDA
9f Member, Council for International Organizations of Medical Sciences (CIOMS) Work Group XIII on Real-World Data & Evidence in Regulatory Decision Making
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15 Courses Led:
34 EPID 7050 Grant Writing & Scientific Writing
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f Honors:
80 1998 Stanley A. Edlavitch Award for Best Abstract Submitted by a Student, International Society for Pharmacoepidemiology
7b 2002 Saul Winegrad Award for Outstanding Dissertation in Epidemiology and Biostatistics, University of Pennsylvania
4c 2005 Young Alumnus Award, University of the Sciences in Philadelphia
70 2008 Leon I Goldberg Young Investigator Award, American Society for Clinical Pharmacology & Therapeutics
7c 2013 Samuel Martin Health Evaluation Sciences Research Award, University of Pennsylvania Perelman School of Medicine
9d 2014 Julius W. Sturmer Memorial Lecture Award, Alpha Tau Chapter of the Rho Chi Society, Philadelphia College of Pharmacy, University of the Sciences
39 2015 Elected Member, National Academy of Medicine
82 2024 William B. Abrams Award in Geriatric Clinical Pharmacology, American Society for Clinical Pharmacology & Therapeutics
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ea Chu PY, Kelly A, Hennessy S, Vajravelu ME, Huang J, Amaral S: GLP-1RA dispensing in youth With type 2 diabetes: 2020 to 2023. Pediatrics Page: e2025071971, 2026.
18f Vo T-T1, Roy S, Ye T, Erterfaie A, Pham Nguyen TP, Flory J, Leonard CE, Small DS and Hennessy S: Effect of exogenous testosterone on cardiovascular, cerebrovascular, and thromboembolic adverse events: Results of three complementary research designs. American Journal of Epidemiology 2025 (https://doi.org/10.1093/aje/kwaf098).
152 Mahoney KM, Bravo L, McAllister A, Bogar K, Hennessy S, Schreiber CA, Abernathy A: Reproductive health services in abortion-providing clinics: A scoping review of provision and policy contexts. Women's Health Issues 2025 (https://doi.org/10.1016/j.whi.2025.07.007).
157 Meng LC, Leonard CE, Candon M, Mandell DS, Hennessy S: Trends in psychotropic medication use, polypharmacy, and potential major drug-drug interactions among US youth. Journal of the American Academy of Child & Adolescent Psychiatry 2025 (doi:10.1016/j.jaac.2025.12.006).
17f Rothstein A, Khazaal O, Messe S, Liu Y, Hennessy S, Chen Y, Algra A, Uchiyama S, Poli S, Geisler T, Serna Higuita LM, Perera K, Taylor A, Kasner SE: Switching from aspirin monotherapy after noncardioembolic stroke: A systematic review and network meta-analysis. Stroke 2025 (doi: 10.1161/STROKEAHA.125.053030).
11e Hsu Y-C, Thakrar AP, Leonard CE, Lowenstein M, Brensinger CM, Bilker WB, Bogar KF, Hennessy S: Trends in methadone use for pain and opioid use disorder among Medicaid enrollees. JAMA Health Forum 6: e244023, 2025.
11f Srivastava T, Harris RA, Bettigole C, Zhang H, Brensinger CM, Bogar K, Wang F, Nesoff ED, Bilker WB, Hennessy S: Stimulant overdose prediction model for Medicaid-insured persons. JAMA Health Forum 6: e253489, 2025.
1c6 Dublin S, Albertson-Junkans L, Pham Nguyen TP, Pavon JM, Hastings SN, Maciejewski ML, Willis A, Zepel L, Hennessy S, Albers KB, Mowery D, Clark AG, Thomas S, Steinman MA, Boyd CM, Bayliss EA: Defining key deprescribing measures from electronic health data: A multisite data harmonization project. Journal of the American Geriatrics Society 2024 (https://doi.org/10.1111/jgs.19280).
13a Zhang H, Miano TA, Bilker WB, Leonard CE, Hennessy S: Grace periods and exposure misclassification in self-controlled case-series studies of drug-drug interactions. American Journal of Epidemiology 2024 (https://doi.org/10.1093/aje/kwae231).
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Selected Publications
127 Thelen HE, Yang W, Hennessy S, Cohen J, Guo W, Miano T: Comparison of disease risk score methods to study treatment effect heterogeneity: a simulation study. American Journal of Epidemiology 2026 (doi:10.1093/aje/kwag050).ea Chu PY, Kelly A, Hennessy S, Vajravelu ME, Huang J, Amaral S: GLP-1RA dispensing in youth With type 2 diabetes: 2020 to 2023. Pediatrics Page: e2025071971, 2026.
18f Vo T-T1, Roy S, Ye T, Erterfaie A, Pham Nguyen TP, Flory J, Leonard CE, Small DS and Hennessy S: Effect of exogenous testosterone on cardiovascular, cerebrovascular, and thromboembolic adverse events: Results of three complementary research designs. American Journal of Epidemiology 2025 (https://doi.org/10.1093/aje/kwaf098).
152 Mahoney KM, Bravo L, McAllister A, Bogar K, Hennessy S, Schreiber CA, Abernathy A: Reproductive health services in abortion-providing clinics: A scoping review of provision and policy contexts. Women's Health Issues 2025 (https://doi.org/10.1016/j.whi.2025.07.007).
157 Meng LC, Leonard CE, Candon M, Mandell DS, Hennessy S: Trends in psychotropic medication use, polypharmacy, and potential major drug-drug interactions among US youth. Journal of the American Academy of Child & Adolescent Psychiatry 2025 (doi:10.1016/j.jaac.2025.12.006).
17f Rothstein A, Khazaal O, Messe S, Liu Y, Hennessy S, Chen Y, Algra A, Uchiyama S, Poli S, Geisler T, Serna Higuita LM, Perera K, Taylor A, Kasner SE: Switching from aspirin monotherapy after noncardioembolic stroke: A systematic review and network meta-analysis. Stroke 2025 (doi: 10.1161/STROKEAHA.125.053030).
11e Hsu Y-C, Thakrar AP, Leonard CE, Lowenstein M, Brensinger CM, Bilker WB, Bogar KF, Hennessy S: Trends in methadone use for pain and opioid use disorder among Medicaid enrollees. JAMA Health Forum 6: e244023, 2025.
11f Srivastava T, Harris RA, Bettigole C, Zhang H, Brensinger CM, Bogar K, Wang F, Nesoff ED, Bilker WB, Hennessy S: Stimulant overdose prediction model for Medicaid-insured persons. JAMA Health Forum 6: e253489, 2025.
1c6 Dublin S, Albertson-Junkans L, Pham Nguyen TP, Pavon JM, Hastings SN, Maciejewski ML, Willis A, Zepel L, Hennessy S, Albers KB, Mowery D, Clark AG, Thomas S, Steinman MA, Boyd CM, Bayliss EA: Defining key deprescribing measures from electronic health data: A multisite data harmonization project. Journal of the American Geriatrics Society 2024 (https://doi.org/10.1111/jgs.19280).
13a Zhang H, Miano TA, Bilker WB, Leonard CE, Hennessy S: Grace periods and exposure misclassification in self-controlled case-series studies of drug-drug interactions. American Journal of Epidemiology 2024 (https://doi.org/10.1093/aje/kwae231).
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