Research


Associate Professor
Department of Systems, Populations and Leadership
Room 4352 NURS1

University of Michigan School of Nursing
400 North Ingalls Building
Ann Arbor, MI 48109-5482

Telephone: (734) 764-8248
Geoffrey Hoffman is accepting new PhD students.

In the news

Interests

  • Aging
  • Injury/safety
  • Family and friend caregiving
  • Medicare programs and payment policy
  • Alzheimer's disease

Dr. Hoffman is a health services researcher and gerontologist. His research focuses on quality of care and Medicare policies affecting physical functioning and safety for older adults. Specific topics of interest include the prevalence, risks, and outcomes associated with fall injuries, implications of family and friend caregiving for older adult injury prevention, well-being, and interactions with the healthcare system, and how Medicare reimbursements influence older individuals' long-term functioning, safety, and care patterns.

Dr. Hoffman's work has been published in leading health services and gerontological journals such as JAMA Network Open, the Journal of General Internal Medicine, Journal of the American Geriatrics Society, Journal of Aging and Health, Medical Care, Health Services Research, and The Gerontologist.

Current Research Grants and Programs

  • MCubed University of Michigan (Hoffman, PI); Health equity and financial incentives: disrupting policy with big data
  • Elsie Anderson Fiske Research Fund (Hoffman, PI) Treatment Patterns and Trajectories in Functioning and Cognitive Status among Older Individuals with Dementia, according to Care Receipt and Minority Status
  • (Bynum, PI) DHHS-NIH. Center to Accelerate Population Research in Alzheimer’s (CAPRA); pilot award to examine informal care patterns for older adults with dementia

Teaching

Dr. Hoffman teaches the nursing Ph.D. course on research methodology (HS852), which covers conceptual models and statistical models for health services research, and statistics for nursing undergraduate students. He has frequently guest lectured on U.S. health care policy and financing and conduct of observational research using secondary data.

Affiliations / Service

  • Member, AcademyHealth, 2010-present
  • Member, American Public Health Association, 2010-present

Notable Awards / Honors

  • HSR Best of AcademyHealth for abstract, "Impact of Medicare Eligibility on Informal Caregiving for Surgery and Stroke," 2021.
  • HSR Best of AcademyHealth for abstract, "Are Improvements Still Needed to the Modified Hospital Readmissions Reduction Program: a Health and Retirement Study (2000-14)?", 2020
  • James G. Zimmer New Investigator Award from the Aging & Health Section of the American Public Health Association, 2017
  • Honorable Mention, James G. Zimmer New Investigator Award from the Aging & Health Section of the American Public Health Association, 2013
  • AcademyHealth Public Health Systems Research Scholarship, 2013

Education

  • Post-doc, University of Michigan School of Nursing, 2017
  • Ph.D., UCLA Fielding School of Public Health, 2015
  • MPH, UCLA Fielding School of Public Health, 2008
  • BA, Harvard University, Cambridge, MA 1994

Publication Highlights

  • Abrams L, Hoffman GJ. Post-hospital care intensity modifies the relationship between depressive symptoms and hospital readmissions but not health outcomes among older adults. Journal of Aging and Health. In press.

  • Hoffman GJ, Nuliyalu U, Bynum J, Ryan AM.  Alzheimer’s Disease and Related Dementias and episode spending under Medicare’s Bundled Payment for Care Improvements Advanced (BPCI-A). Journal of General Internal Medicine. In press.

  • Hsuan C, Ponce N, Braun T, Hoffman GJ. Are Improvements Still Needed to the Modified Hospital Readmissions Reduction Program: a Health and Retirement Study (2000-14)? Journal of General Internal Medicine. 2020;35(12); 356-3571.

  • Harris ML, Titler MG, Hoffman GJ. Associations Between Alzheimer's Disease and Related Dementias and Depressive Symptoms of Partner Caregivers. J Appl Gerontol. 2020 Aug 29:733464820952252.

  • Hoffman GJ, Webster NJ, Bynum JPW. A Framework for Aging-Friendly Services and Supports in the Age of COVID-19. J Aging Soc Policy. 2020:1-10.

  • Hoffman GJ, Tinetti ME, Ha J, Alexander NB, Min LC. Prehospital and Posthospital Fall Injuries in Older US Adults. JAMA Netw Open. 2020 Aug 3;3(8):e2013243.

  • Hoffman GJ, Yakusheva O. Association Between Financial Incentives in Medicare's Hospital Readmissions Reduction Program and Hospital Readmission Performance. JAMA Netw Open. 2020;3(4):e202044.

  • Hsuan C, Carr B, Hsia RY, Hoffman GJ. The Role of the Emergency Department in Hospital Readmissions Following Implementation of Medicare’s Hospital Readmissions Reduction Program. JAMA Netw Open. 2020;3(5):e203857.

  • Sukul D, Hoffman GJ, Nuliyalu U, et al. Association Between Medicare Policy Reforms and Changes in Hospitalized Medicare Beneficiaries' Severity of Illness. JAMA Network Open. 2019;2(5):e193290.

  • Hoffman GJ, Hsuan C, Braun T, Ponce N, “Heath Equity and Hospital Readmissions: Does Inclusion of Patient Functional and Social Complexity Improve Predictiveness?” Journal of General Internal Medicine. 2019;34(1):26-28.

  • Yakusheva O, Hoffman GJ. A reduction in readmissions results in net savings for most hospitals, an examination of Medicare’s hospital readmissions reduction program.  Medical Care Research and Review. 2020;77(4):334-344.

  • Hoffman GJ, Tilson S, Yakusheva O. The financial impact of an avoided readmission for teaching and safety-net hospitals under Medicare’s hospital readmission reduction program.  Medical Care Research and Review. 2020;77(4):324-333.

  • Hoffman GJ, Ha J, Alexander NB, Langa KM, Tinetti M, Min LC. Underreporting of Fall Injuries of Older Adults: Implications for Wellness Visit Fall Risk Screening. Journal of American Geriatrics Society. 2018;66(6):1195-1200.

  • Hoffman, G. J., Hays, R. D., Shapiro, M. F., Wallace, S. P., & Ettner, S. L. (2016). The costs of fall-related injuries among older adults: Annual per-faller, service component, and patient out-of-pocket costs. Health Services Research. 2017;52: 1794-1816.

  • Hoffman, G. J., Hays, R. D., Shapiro, M. F., Wallace, S. P., & Ettner, S. L. (2016). Claims-based identification methods and the cost of fall-related injuries among US older adults. Medical Care. 54(7), 664-671.

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Associate Professor
Department of Health Behavior and Clinical Sciences
Room 2150 NURS1

University of Michigan School of Nursing
400 North Ingalls Building
Ann Arbor, MI 48109-5482

Telephone: (734) 647-0151
Fax: (734) 936-5525
Akshay Sharma is accepting new PhD students.

Interests

  • HIV and STI prevention
  • Sexual and gender minority health
  • Remote health interventions
  • Health promotion and behavior change
  • Infectious disease epidemiology

Educated as a physician and an infectious disease epidemiologist, Dr. Sharma’s research interests include designing and evaluating new approaches for increasing the frequency of HIV and STI testing among sexual and gender minorities in the United States, with a focus on telehealth and home self-testing. He is also interested in comprehensive behavioral and biomedical interventions for HIV and STI prevention, barriers and facilitators to accessing healthcare, and epidemiologic study design and methodological issues. He is involved in both quantitative and qualitative research that seeks to further our understanding of novel means of delivering sexual health promotion and behavior change strategies to populations at elevated risk. Before moving to the United States, Dr. Sharma was involved in community HIV and STI risk reduction efforts such as encouraging safe sex and promoting the use of barrier contraceptives in resource-limited settings in India.

Teaching

Dr. Sharma strives for effectiveness and excellence in his pedagogical techniques. He employs an interactive approach in the classroom that emphasizes active participation using mobile and online technologies. He has taught several graduate epidemiology courses at Emory University and undergraduate anatomy and physiology, pathophysiology, and microbiology and infectious disease courses at the University of Michigan. The combination of Dr. Sharma’s medical and epidemiological background allows him to bring a unique perspective to these subjects. He has worked closely with students from varying academic, cultural, and demographic backgrounds, and believes that engaging them in a supportive environment facilitates better learning and enhances retention. In recognition of his notable contributions to pedagogy, Dr. Sharma was honored with the 2020 Mae Edna Doyle Teacher of the Year Award and the 2023 Inclusive Teaching Award.

Affiliations / Service

  • Delta Omega Honorary Society in Public Health, 2010 - present
  • International AIDS Society, 2015 - present
  • European AIDS Clinical Society, 2017 - present
  • American Public Health Association, 2019 - present
  • Transgender Health Editorial Board Member, 2019 - present

Notable Awards / Honors

  • University of Michigan School of Nursing, 2023 Inclusive Teaching Award, 2023
  • International AIDS Society, 2022 International AIDS Society Mentorship Programme Mentor, 2022
  • American Public Health Association HIV/AIDS Section, 2021 Excellence in Abstract Submission among All Presenters Honorable Mention Award, 2021
  • University of Michigan School of Nursing, 2020 Mae Edna Doyle Teacher of the Year Award, 2020
  • Texas Public Health Association and Texas Department of State Health Services, 2014 Texas HIV/STD Student Research Award, 2014
  • Delta Omega Honorary Society in Public Health, 2010 Inductee to the Emory University Phi Chapter, 2010

Education

  • Postdoctoral Fellow, Epidemiology, Emory University Rollins School of Public Health, Atlanta, Georgia, United States
  • Ph.D., Epidemiology, Emory University Laney Graduate School, Atlanta, Georgia, United States
  • M.P.H., Epidemiology, Emory University Rollins School of Public Health, Atlanta, Georgia, United States
  • M.B.B.S., Medicine and Surgery, Bangalore Medical College and Research Institute, Bangalore, Karnataka, India

Publication Highlights

  • Sharma, A., Gebrezgi, F., Hamilton, A., Boyd, S., & Sallabank, G. (2024). HIV-related knowledge, risk perception, and minority stressors among South Asian sexual minority men in the United States. International Journal of STD & AIDS, 35(12), 944-951.

  • Sharma, A., Lacombe-Duncan, A., & Sallabank, G. (2023). HIV and STI testing among South Asian gay, bisexual, and other men who have sex with men in the United States. American Journal of Men's Health, 17(3). 

  • Sharma, A., Gandhi, M., Sallabank, G., Merrill, L., & Stephenson, R. (2023). Perceptions and experiences of returning self-collected specimens for HIV, bacterial STI and potential PrEP adherence testing among sexual minority men in the United States. AIDS and Behavior, 27(4), 1091-1105.

  • Sharma, A., Gandhi, M., Sallabank, G., Merrill, L., & Stephenson, R. (2022). Study evaluating self-collected specimen return for HIV, bacterial STI and potential pre-exposure prophylaxis adherence testing among sexual minority men in the United States. American Journal of Men's Health. 16(4).

  • Sharma, A., Paredes-Vincent, A., & Kahle, E. (2021). Awareness, utilization, and preferences for traditional and contemporary HIV prevention strategies among Facebook and Instagram-using MSM in the United States. Journal of the International Association of Providers of AIDS Care, 20.

  • Sharma, A., Kahle, E., Sullivan, S., & Stephenson R. (2021). Sexual agreements and intimate partner violence among male couples in the US: An analysis of dyadic data. Archives of Sexual Behavior, 50(3), 1087-1105.

  • Sharma, A., Kahle, E., Sullivan, S., & Stephenson, R. (2020). Relationship characteristics associated with perceptions of partners’ HIV testing behavior among male couples. AIDS and Behavior, 24(2), 516-531.

  • Sharma, A., Shaver, J., & Stephenson, R. (2019). Rural primary care providers’ attitudes towards sexual and gender minorities in a Midwestern state. Rural and Remote Health, 19(4).

  • Sharma, A., Garofalo, R., Hidalgo, M. A., Hoehnle, S., Mimiaga, M. J., Brown, E., … & Stephenson, R. (2019). Do male couples agree on their sexual agreements? An analysis of dyadic data. Archives of Sexual Behavior, 48(4), 1203-1216.

  • Sharma, A., Kahle, E.M., Todd, K., Peitzmeier, S., & Stephenson, R. (2019). Variations in testing for HIV and other sexually transmitted infections across gender identity among transgender youth. Transgender Health, 4(1), 46-57.

  • Sharma, A., Kahle, E.M., Sullivan, S., & Stephenson, R. (2018). Birth cohort variations across functional knowledge of HIV prevention strategies, perceived risk, and HIV-associated behaviors among gay, bisexual and other men who have sex with men in the United States. American Journal of Men’s Health, 12(6), 1824-1834.

  • Sharma, A., Chavez, P. R., MacGowan, R. J., McNaghten, A. D., Mustanski, B., Gravens, L., ... & Sullivan, P. S. (2017). Willingness to distribute free rapid home HIV test kits and to test with social or sexual network associates among men who have sex with men in the United States. AIDS Care, 29(12), 1499-1503.

  • Sharma, A., Wang, L. Y., Dunville, R., Valencia, R. K., Rosenberg, E. S., & Sullivan, P. S. (2017). HIV and sexually transmitted disease testing behavior among adolescent sexual minority males: Analysis of pooled Youth Risk Behavior Survey data, 2005-2013. LGBT Health, 4(2), 130-140.

  • Sharma, A., Johnson, B. A., & Sullivan, P. S. (2015). Evaluating interventions to promote routine preventive screenings: A comparison of analytical outcomes. Contemporary Clinical Trials, 41, 152-159.

  • Sharma, A., Stephenson, R. B., White, D., & Sullivan, P. S. (2014). Acceptability and intended usage preferences for six HIV testing options among internet-using men who have sex with men. Springerplus, 3(1).


Adjunct Professor
Department of Systems, Populations and Leadership

University of Michigan School of Nursing
400 North Ingalls Building
Ann Arbor, MI 48109-5482

Interests

  • Mixed modeling
  • Longitudinal studies
  • Addressing the challenges associated with small-n studies in highly novel research areas
  • Missing data issues and analysis
  • Statistical designs and issues related to studying short and long-term effects of microgravity on humans

Dr. Ploutz-Snyder is a member and is among the first 100 professionally accredited statisticians in the American Statistical Association (Pstat®).  He was a lead Biostatistician in NASA’s Human Research Program at the Johnson Space Center, where he collaborated on numerous grants aimed at better understanding and mitigating the negative effects of spaceflight on humans.  Prior to NASA, he was an Associate Professor of Medicine at the SUNY Upstate Medical University in Syracuse, NY, with a highly successful track record of grant collaborations and scholarship.


Associate Professor
Department of Systems, Populations and Leadership
Room 4346 NURS1

University of Michigan School of Nursing
400 North Ingalls Building
Ann Arbor, MI 48109-5482

Telephone: (734) 647-0341
Fax: (734) 763-0681

In the news

Interests

  • Disaster preparedness and response
  • Acute and emergency care
  • Healthcare resilience
  • Aging

Dr. Sue Anne Bell is a nurse scientist and family nurse practitioner, with expertise in disaster response, community health and emergency care. Her research focuses on the health and well-being of aging populations in the context of disasters and public health emergencies. She is serving as a 2024-2025 NIH Visiting Scholar, as well as, on the U.S. Department of Health and Human Service’s National Advisory Council on Seniors and Disasters. Dr. Sue Anne Bell is clinically active in disaster response as a nurse practitioner with the National Disaster Medical System, with over a dozen recent deployments.  

Affiliations / Service

  • National Institutes of Health Visiting Scholar, 2024-2025
  • Voting Member, National Advisory Committee on Seniors and Disasters, U.S. Department of Health and Human Services 2021- present
  • Health Scientist, Federal Emergency Management Agency, National Advisory Council, 2018-2023

Notable Awards / Honors

  • Policy Impact Award, Institute for Healthcare Policy and Innovation, University of Michigan, 2023
  • Civilian Covid Response Medal, U.S. Department of Health and Human Services, 2022
  • Invited testimony to the U.S. Senate Select Committee on Aging, 2021
  • Public Policy Advocate Award, American Nurses Association of Michigan, 2021
  • Nurse Researcher Award, Emergency Nurses Association, 2021
  • Fellow, American Academy of Nursing, 2020

Education

  • Executive Leaders Program, Center for Homeland Defense and Security at the U.S. Naval Postgraduate School, U.S. Department of Homeland Security, Monterey, CA, 2022-2023
  • National Clinician Scholars Program, 2016-2018
  • PhD, University of Michigan, Ann Arbor MI 2014; Graduate Certificate in Women’s Studies 2014
  • MSN, Emory University, Atlanta, GA 1999
  • BSN, The Florida State University, Tallahassee, FL 1997

Publication Highlights

  • Bell, S.A., Kruger, K., Ikari, R., Khunmuench, C., Gates, K., Rosemberg, M.A. (2025). Addressing dementia care needs during the COVID-19 pandemic: Perspectives from home care workers. Journal of Gerontological Nursing.

  • Kruger, K., Rettell, Z., Chang, T., & Bell, S.A. (2025). Youth Perspectives about Readiness for Disaster Events. Traumatology.

  • Bell, S. A., Miranda, M. L., Bynum, J. B., & Davis, M. A. (2023). Mortality following exposure to a hurricane among older adults living with dementia. JAMA Network Open, 6(3), e232042. doi: 10.1001/jamanetworkopen.2023.2043

  • Koman, P. D., Billmire, M., Baker, K. R., Carter, J. M., Thelen, B. J., French, N. H. F., & Bell, S. A. (2022). Using wildland fire smoke modeling data in gerontological health research (California, 2007-2018). Science of The Total Environment, 838(3), 156403. doi: 10.1016/j.scitotenv.2022.156403

  • Bell, S. A., Krienke, L., Brown, A., Inloes, J., Rettell, Z., & Wyte-Lake, T. (2022). Barriers and facilitators to providing home-based care in a pandemic: Policy and practice implications. BMC Geriatrics, 22, 234. doi: 10.1186/s12877-022-02907-w

  • Bell, S. A., Donnelly, J. P., Wang, L., & Davis, M. A. (2022) Hospitalizations for chronic conditions following hurricans among older adults: A self-controlled case series analysis. Journal of the American Geriatrics Society, 70(6), 1695-1703. doi: 10.1111/jgs.17702

  • Bell, S.A., Klaza, K., Iwashyna, T.J., Norton, E., & Davis, M.A. (2020). Long-term healthcare provider availability following large-scale hurricanes: A difference-in-differences study. PLOS One, 15(11):e0242823. doi: 10.1371/journal.pone.0242823

  • Bell, S.A., Banerjee, M., Griggs, J. Iwashyna, T.J., & Davis, M. A. (2020). The effect of exposure to disaster on cancer survival. Journal of General Internal Medicine, 35, 380-382. http://doi.org/10.1007/s11606-019-05465-x

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