Effect of influenza vaccination of nursing home staff on mortality of residents: a cluster-randomized trial.
OBJECTIVE
To evaluate the effect of staff influenza vaccination on all-cause mortality in nursing home residents.


METHODS
Pair-matched cluster-randomized trial.


METHODS
Forty nursing homes matched for size, staff vaccination coverage during the previous season, and resident disability index.


METHODS
All persons aged 60 and older residing in the nursing homes.


METHODS
Influenza vaccine was administered to volunteer staff after a face-to-face interview. No intervention took place in control nursing homes.


METHODS
The primary endpoint was total mortality rate in residents from 2 weeks before to 2 weeks after the influenza epidemic in the community. Secondary endpoints were rates of hospitalization and influenza-like illness (ILI) in residents and sick leave from work in staff.


RESULTS
Staff influenza vaccination rates were 69.9% in the vaccination arm versus 31.8% in the control arm. Primary unadjusted analysis did not show significantly lower mortality in residents in the vaccination arm (odds ratio=0.86, P=.08), although multivariate-adjusted analysis showed 20% lower mortality (P=.02), and a strong correlation was observed between staff vaccination coverage and all-cause mortality in residents (correlation coefficient=-0.42, P=.007). In the vaccination arm, significantly lower resident hospitalization rates were not observed, but ILI in residents was 31% lower (P=.007), and sick leave from work in staff was 42% lower (P=.03).


CONCLUSIONS
These results support influenza vaccination of staff caring for institutionalized elderly people.
Lemaitre
Magali
M
Department of Epidemiology, Information Systems, and Modeling, University Pierre and Marie Curie Paris 6, UMR-S 707, Paris, France.
Meret
Thierry
T
Rothan-Tondeur
Monique
M
Belmin
Joel
J
Lejonc
Jean-Louis
JL
Luquel
Laurence
L
Piette
François
F
Salom
Michel
M
Verny
Marc
M
Vetel
Jean-Marie
JM
Veyssier
Pierre
P
Carrat
Fabrice
F
D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D004185:Disability Evaluation; D004196:Disease Outbreaks / Q000517:prevention & control* / Q000706:statistics & numerical data; D005260:Female; D005602:France; D006707:Homes for the Aged / Q000706:statistics & numerical data*; D006801:Humans; D017589:Immunization Programs; D017757:Infectious Disease Transmission, Professional-to-Patient / Q000517:prevention & control* / Q000706:statistics & numerical data; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000401:mortality / Q000451:nursing* / Q000517:prevention & control* / Q000635:transmission; D008297:Male; D016555:Matched-Pair Analysis; D009735:Nursing Homes / Q000706:statistics & numerical data*; D009740:Nursing Staff / Q000706:statistics & numerical data*; D018582:Sick Leave; D016019:Survival Analysis
D007252:Influenza Vaccines