http://orcid.org/0000-0001-6000-6859
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ABSTRACT
Influenza severity increases and vaccine effectiveness decreases with age. High-dose influenza vaccine (HD) with quadruple the antigen of standard-dose (SD) vaccine is more efficacious in community-dwelling persons 65 years and older. We evaluated the feasibility of recruiting and randomizing Medicare certified nursing homes (NHs) for a pragmatic cluster-randomized trial comparing HD vs. SD (NCT1720277). Residents were long-stay and at least 65 years old. NH leadership agreed to standard of care random assignment with HD (Fluzone® High-Dose) or SD (Fluzone®) influenza vaccine for their facility for the 2012–2013 influenza season. We used Minimum Data Set (MDS) 3.0 and Vital Status records for pre-specified clinical outcomes: 1) all-cause hospitalization, 2) NH mortality, and 3) functional decline. Intent-to-treat analyses were performed at the resident-level using Cox proportional hazards, multivariable Poisson, and logistic regression models accounting for clustering by facility. We randomized 39 NHs (19 SD and 20 HD), coordinated vaccine delivery, implemented web-based data collection, and accessed MDS data, demonstrating feasibility. There were 2,957 eligible residents (SD 1496; HD 1461); characteristics were similar between groups. A total of 301 (20.1%) of SD and 197 (13.5%) of HD allocated residents were ever hospitalized, (adjusted relative risk 0.680; 95% CI: 0.537, 0.862; p = 0.001). NH mortality was 274 (18.3%) SD vs. 249 (17.1%) HD, adjusted relative risk 0.834; 95% CI: 0.678, 1.027; p = 0.087). There were no differences in decline in functional status (13.4 vs. 13.8%, adjusted relative risk 0.994; 95% CI: 0.774,1.278; p = 0.965). We demonstrate that a pragmatic large-scale trial is feasible in a NH setting.
Disclosure of potential conflicts of interest
No potential conflicts of interest were disclosed.
Acknowledgments
Joanne Stewart, Insight Therapeutics, LLC, for review of the final manuscript.
Funding
Funded by an investigator-initiated (SG) grant from Sanofi Pasteur, Swiftwater, PA.
Author contributions
Study concept and design: S. Gravenstein, V. Mor
Acquisition of data: L. F. Han, H. E. Davidson, J. A. Ogarek, P. L. Gozalo
Analysis and interpretation of data: All authors.
Drafting of the manuscript: R. Dahal, S. Gravenstein
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: R. Dahal, J. A. Ogarek, P. L. Gozalo, M. Taljaard, V. Mor, S. Gravenstein
Obtaining funding: H. E. Davidson, S. Gravenstein, V. Mor
Study supervision: H. E. Davidson, L. Han, S. Gravenstein, V. Mor
Sponsor's role
The study was supported by an investigator-initiated grant from Sanofi Pasteur to Insight Therapeutics, LLC. Sanofi Pasteur had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The corresponding author had full access to all the data in the study.
Data results presented as a Late Breaker Oral Abstract Session, Saturday, October 10, 2015, at the Infectious Disease Society of America's ID Week 2015, San Diego, CA.