543. High-Dose Influenza Vaccination and Morbidity and Mortality in U.S. Nursing Homes: A Pilot Cluster Randomized Controlled Trial
Session: Poster Abstract Session: Respiratory Viruses
Thursday, October 8, 2015
Room: Poster Hall
  • Poster.pdf (436.8 kB)
  • Background:  Influenza (FLU) severity increases and vaccine effectiveness decreases with age. High-Dose (HD) FLU vaccine has quadruple the antigen of standard-dose (SD) FLU vaccine and is significantly more immunogenic and effective in persons ≥ 65 years of age. Establishing relative clinical effectiveness in a long-term care population presents logistical challenges. We piloted a pragmatic cluster RCT to evaluate feasibility of a large-scale comparison between SD and HD FLU vaccines. 

    Methods:  Medicare-certified nursing homes (NHs), within 50 miles of a CDC FLU reporting city, not planning to vaccinate their long-term residents with HD FLU vaccine were eligible to participate. NHs leadership agreed to random assignment to either HD (Fluzone® High-Dose vaccine) or SD (Fluzone® vaccine) as their standard of care for all seniors in the NHs. Residents ≥ 65 years of age living in study NHs for > 90 days were included for analysis. We used Minimum Data Set 3.0 records to determine pre-specified outcomes: 1) all-cause hospitalization, 2) in NH mortality, and 3) functional decline. Intent-to-treat analyses were performed at the resident-level using Cox proportional hazards and multivariable Poisson and logistic regression models accounting for clustering by facility (SAS 9.4).

    Results:  We randomized 39 NHs (19 SD and 20 HD) during the study period (Oct 2012–Mar 2013), housing 2,957 eligible residents, among whom 75% were women and 79% were white; characteristics were similar between groups. During the study period, 20.1% of SD residents and 13.5% of HD residents were ever hospitalized. Differences in proportion of residents hospitalized were largest for residents 65-78 and > 91 years old. Residents in the HD group were 30% less likely to have any hospitalization compared with the SD group (adjusted relative risk 0.701; 95% CI: 0.543, 0.905; p=0.006). Study period within-NH mortality and 4-point decline in functional status were similar (p=0.650, p=0.743, respectively).

    Conclusion:  This pilot study demonstrated that a pragmatic large-scale trial is feasible in a NH setting and can detect differences in overall hospitalization rates following HD and SD FLU vaccination.

    Trial registration: Clinical Trials NCT01815268

    Funding: Unrestricted grant from Sanofi Pasteur

    Stefan Gravenstein, MD, MPH1,2,3, Roshani Dahal, MPH2, Pedro Gozalo, PhD4, Monica Taljaard, PhD5,6, H. Edward Davidson, PharmD, MPH7, Lisa Han, MPH7, Jessica Ogarek, MS2 and Vincent Mor, PhD4,8, (1)Medicine, Geriatrics, Case Western Reserve University, Cleveland, OH, (2)Center for Gerontology and Healthcare Research, Brown University School of Public Health, Providence, RI, (3)Center for Geriatric Medicine, UH Case Medical Center, Cleveland, OH, (4)Department of Health Services, Policy & Practice, Brown University School of Public Health, Providence, RI, (5)Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada, (6)Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON, Canada, (7)Insight Therapeutics, LLC, Norfolk, VA, (8)Providence VA Medical Center, Providence, RI


    S. Gravenstein, Sanofi Pasteur: Consultant , Grant Investigator , Scientific Advisor and Speaker's Bureau , Consulting fee , Grant recipient , Research support and Speaker honorarium
    Merck: Scientific Advisor , Consulting fee

    R. Dahal, None

    P. Gozalo, None

    M. Taljaard, None

    H. E. Davidson, sanofi pasteur: Research Contractor , Research support

    L. Han, Sanofi Pasteur: Research Contractor , Research grant

    J. Ogarek, None

    V. Mor, None

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