[Effectiveness of influenza vaccine in the elderly. A critical review of the bibliography].
BACKGROUND
The acceptance of influenza vaccine has been slow as doubts about its effectiveness persist. The goal of this study is to review the existing evidence on influenza vaccine effectiveness in preventing pneumonia and influenza hospitalizations in non institutionalized elderly.


METHODS
We have conducted a search in MEDLINE, including a period between 1984 and 1994, and of cross references, between 1980 and 1994. Twelve studies have been identified and valued independently by the authors. The results are combined through a graphic representation and the quantitative method proposed by Woolf.


RESULTS
Four studies have been excluded; two, because they did not satisfy the comparability principle; one, because it was a publication already published; and one because of small numbers. According to the graphic method, influenza vaccine prevents between 29 and 51 percent of pneumonia and influenza hospitalizations in the non institutionalized elderly. When results are integrated by the quantitative method, the odds ratio is 0.63 (CI 95%, 0.54 to 0.72). The percentage of pneumonia and influenza hospitalizations prevented by the influenza vaccine equals 37.40% (CI 95%, 27.81% to 45.72%) in the vaccinated.


CONCLUSIONS
The annual influenza immunization of those 65 years old or older is an effective primary prevention strategy.
Puig Barberà
J
J
Unidad de Programas de Promoción de Salud, Dirección de Atención Primaria Area 02, Conselleria de Sanitat i Consum, Generalitat Valenciana.
Márquez Calderón
S
S
D000368:Aged; D006801:Humans; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000517:prevention & control*
D007252:Influenza Vaccines
Efectividad de la vacunación antigripal en los ancianos. Una revisión crítica de la bibliografía.