Research
University of Michigan School of Nursing
400 North Ingalls Building
Ann Arbor, MI 48109-5482
In the news
Jun 18, 2025: CNN "Older adults in the US are increasingly dying from unintentional falls"
Jun 2, 2025: University of Michigan Institute for Healthcare Policy & Innovation "What makes someone leave a Medicare Advantage plan?"
Oct 24, 2024: University of Michigan Institute for Healthcare Policy & Innovation "Medicare has a revolving door, study suggests"
Mar 20, 2024: University of Michigan Institute for Healthcare Policy & Innovation "In sickness and in health, older couples mostly make Medicare moves together"
Sep 2, 2020: Michigan News "Depression worsens over time for older caregivers of newly diagnosed dementia patients"
Aug 19, 2020: Michigan News "Balancing act: falls often early signal of underlying health problems"
Jul 9, 2020: Stateside "For older adults, social distancing brings its own mental and physical health risks."
Interests
- Medicare Advantage
- Alzheimer's disease
- Injury/safety
- Health policy
- Caregiving
Dr. Hoffman is a health services researcher and gerontologist. His research focuses on quality of care and Medicare policies affecting utilization and injury for older adults. Specific topics of interest include how Medicare reimbursements and insurance arrangements (Traditional Medicare and Medicare Advantage) 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 Health Affairs, 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
- The impact of Medicare managed care on older patients with dementia and their family caregivers (NIA R01AG074944; PI)
- The effects of bundled payment on acute cardiovascular outcomes among older adults (NIA R01AG047932; Co-I)
- Effects of the COVID-19 Pandemic on Long-Term Care for High-Need Older Adults with and without Alzheimer's Disease and Related Dementias (NIA R01AG0805801; Co-I)
- Resilience to Covid-19 Disrupted Chronic Condition Care for Older Veterans At Risk of Hospitalization: Role of VA Ambulatory Care and VA Extended Care Home and Community-Based Care Supports (VA I01 HX003584)
Teaching
Dr. Hoffman teaches the nursing Ph.D. course on research methodology (HS852), which covers conceptual models and statistical models for health services research. 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
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
Hoffman, G.J., Lei, L., Alam, I., Kim, M., Min, L., Fan, Z., & Levine, D. (2025). Medicare Advantage Plan Disenrollment: Beneficiaries cite access, cost, and quality among reasons for leaving. Health Affairs, 44(6), 684-692. doi:10.1377/hlthaff.2024.01536
Hoffman, G.J., Jiao, Y.A., Fan, Z., Kim, H.M., Min, L., & Maust, D. (2024). Should I stay or should I go again: Multiple switching between fee-for-service Medicare and Medicare advantage among older beneficiaries. Health Services Research, 60(Suppl. 2), e14398. doi:10.1111/1475-6773.14398.
Hoffman, G.J. & Fendrick, A.M. (2025). The consequences of the Kennedy v. Braidwood Supreme Court ruling on fall prevention. Journal of the American Geriatrics Society. doi:10.1111/jgs.19576.
Hoffman, G.J., Ha, J., Fan, Z., & Li, J. (2025). Associations between rural hospital closures and acute and post-acute care access and outcomes. Health Services Research, 60(3), e14426. doi: 10.1111/1475-6773.14426.
Hoffman, G.J., Ha, J., & Li, J. (2024). Association of Medicare home health ratings with older adult fall injuries: An instrumental variables analysis. Journal of the American Medical Directors Association, 25(7), 105013. doi: 10.1016/j.jamda.2024.03.123.
Lei, L., Levy. H., Ankuda, C., Hoffman, G.J., Kim, M., Strominger, J., & Maust, D. (2024). Partner plan choices and Medicare Advantage enrollment decisions among older adults. JAMA, 331(15), 1322-1325. doi: 10.1001/jama.2024.1773.
Hoffman, G.J., Alexander, N.B., Ha, J., Nguyen, T., & Min, L.C. (2023). Medicare’s hospital readmission reduction program reduced fall-related health care use: An unexpected benefit? Health Services Research, 59(1), e14246. doi: 10.1111/1475-6773.14246.
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University of Michigan School of Nursing
400 North Ingalls Building
Ann Arbor, MI 48109-5482
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).
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.
University of Michigan School of Nursing
400 North Ingalls Building
Ann Arbor, MI 48109-5482
In the news
October 2, 2024: Hurricane Helene Deaths Will Continue for Years, Study Suggests. Interview. New York Times.
December 30, 2023: Pack Your Memories Into Your Disaster Bag. Interview. The Atlantic.
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
