[Evolution of the degrees of influenza vaccine (flu shot) coverage in Spain throughout the 1993-2001 period. Analysis by Autonomous Communities].

Background: Influenza (flu) is a disease involving a high morbidity which takes a high toll on healthcare costs for which there is an effective vaccine available. This study is aimed at evaluating the evolution of the different degrees of influenza vaccine (flu shot) coverage in Spain by Autonomous Communities during the 1993-2001 period.

Methods: A total of 42,123 cases from the National Health Survey (NHS) for the years 1993 (n=21,051) and 2001 (n=21,072) were analysed, all of which corresponded to non-institutionalised Spanish adults over 15 years of age. Both surveys are representative at the Autonomous Community level.

Results: For the total sample, a vaccine coverage of 17.94% (CI 95% 17.42-18.46) in 1993 and of 19.30% (18.77-19.83) en 2001 was estimated. In the logic regression model, adjusted by age, sex and related chronic disease, significant improvements were found in the degrees of coverage of individuals over 64 years of age (OR = 1.28 CI 95% 1.10-1.50) for Spain as a whole and for five of the seventeen Autonomous Communities between 1993 and 2001. However, no significant changes were found in the degrees of coverage for the group under age 65 with related chronic disease entailing an indication for being administered the vaccine.

Conclusions: A slight yet insufficient improvement in the degrees of coverage among the high-risk groups studied were found to exist both nation-wide in Spain as a whole as well as in the majority of the Autonomous Communities between 1993 and 2001. Degrees of coverage varied greatly among Autonomous Communities. The individual under age 65 with related chronic diseases heightening the risks of suffering from flu-related complications have not improved their degrees of coverage regarding this vaccine during the period studied. The difficulty involved in improving the degrees of coverage among this type of patients might lead us to consider the alternative and potential benefit of lowering the age limit of the current influenza vaccine (flu shot) indication-related recommendations in Spain.