[Effectiveness of an anti-influenza vaccination program in 4 primary care centers]

A influenza immunization programme held in 4 health centres is evaluated, by testing the hypothesis that programme compliance lowers their hospital admissions and mortality. A cohort of 4,558 people over 65 belonging to 4 "Baix Llobregat" health centres was followed-up during 7 months. The population covered by immunization programme (43.8%) showed a hospital admission rate (6.2%) lower than the non immunized one (4.3%). Nevertheless, the cardiorespiratory disease admission rate in the whole sample (2.0% in immunized and 1.3% in non immunized), and in females (1.3% in immunized and 1.2 in non immunized) didn't show differences between covered and non covered by the programme. Mortality is lower in compliant (0.8% in immunized, and 1.9% in non immunized), but it's due to a higher death rate in the counted unimmunized, non demanding, and non hospital admitted population. If we interpret these data as the immunization covered population is more health services consumer, we can consider that at least in women, the programme has a contention effect for cardiorespiratory disease hospital admission. The mortality drop can not be attributed to immunization but it will be due to the health centers incapacity for reaching the high risk population of the assigned community. On the basis of these results, health centers should reconsider the need for continuing carry out these immunizations programmes. Primary Health care teams should establish programmes that would allow them to cover the assigned community health needs, even for non demanded services.