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
Merck: Scientific Advisor , Consulting fee
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