title: Influenza vaccination among the elderly Spanish population: trend from 1993 to 2003 and vaccination-related factors.
abstract: BACKGROUND
  Influenza is an important public health problem that particularly affects elderly subjects and influenza vaccination is a safe, effective and efficient method for prevention of influenza-related complications in elderly individuals with or without underlying chronic conditions. This study aims to analyze adjusted time trends in the coverage of influenza vaccination among elderly Spanish subjects and to identify which variables were associated with the probability of having been vaccinated in 2003.
  
  
  METHODS
  We undertook a cross-sectional study using data of individuals aged >/=65 years drawn from the 1993, 1995, 1997, 2001, and 2003 Spanish National Health Surveys. The answer to the question 'Did you have a 'flu shot in the latest campaign' was used as the dependent variable, and socio-demographic and health-related characteristics were analyzed as independent variables. Coverage of vaccination for each year was adjusted by the direct method for both age and gender. Multivariate logistic regression was used to estimate the independent effect of variables on the receipt of influenza vaccine.
  
  
  RESULTS
  15 989 records were analyzed. Adjusted influenza coverage increased from 50.1% in 1993 to 63.7% in 2003 (P < 0.001). The variables that were significantly associated with a higher likelihood of being vaccinated were older age, suffering a chronic disease, residence in towns with <10 000 inhabitants, 'worse' self-perceived health and non-smokers.
  
  
  CONCLUSIONS
  Coverage among the Spanish elderly has increased significantly from 1993 to 2003. Still, there is room for improvement, particularly, among the subjects with 'good' self-perceived health, those with no concomitant medical conditions, and smokers.
authors.affiliation: Preventive Medicine Unit, Alfonso X el Sabio University, Villanueva de la Cañada Campus Madrid, Spain.
authors.forename: Ana Lopez
authors.initials: AL
authors.lastname: de Andres
authors.forename: Pilar Carrasco
authors.initials: PC
authors.lastname: Garrido
authors.forename: Valentín
authors.initials: V
authors.lastname: Hernández-Barrera
authors.forename: Silvia Vázquez-Fernández
authors.initials: SV
authors.lastname: Del Pozo
authors.forename: Angel Gil
authors.initials: AG
authors.lastname: de Miguel
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Jiménez-García
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D005260:Female; D019538:Health Care Surveys; D006297:Health Services Accessibility; D006801:Humans; D017589:Immunization Programs / Q000706:statistics & numerical data*; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000517:prevention & control*; D016015:Logistic Models; D008297:Male; D010342:Patient Acceptance of Health Care / Q000523:psychology / Q000706:statistics & numerical data*; D011156:Population Density; D012424:Rural Population / Q000706:statistics & numerical data; D012959:Socioeconomic Factors; D013030:Spain; D014505:Urban Population / Q000706:statistics & numerical data; D014611:Vaccination / Q000706:statistics & numerical data*
chemical_list: D007252:Influenza Vaccines