title: Social factors related to the clinical severity of influenza cases in Spain during the A (H1N1) 2009 virus pandemic.
abstract: BACKGROUND
  During the 2009 influenza pandemic, a change in the type of patients most often affected by influenza was observed. The objective of this study was to assess the role of individual and social determinants in hospitalizations due to influenza A (H1N1) 2009 infection.
  
  
  METHODS
  We studied hospitalized patients (cases) and outpatients (controls) with confirmed influenza A (H1N1) 2009 infection. A standardized questionnaire was used to collect data. Variables that might be related to the hospitalization of influenza cases were compared by estimation of the odds ratio (OR) and 95% confidence intervals (CI) and the variables entered into binomial logistic regression models.
  
  
  RESULTS
  Hospitalization due to pandemic A (H1N1) 2009 influenza virus infections was associated with non-Caucasian ethnicity (OR: 2.18, 95% CI 1.17 - 4.08), overcrowding (OR: 2.84, 95% CI 1.20 - 6.72), comorbidity and the lack of previous preventive information (OR: 2.69, 95% CI: 1.50 - 4.83). Secondary or higher education was associated with a lower risk of hospitalization (OR 0.56, 95% CI: 0.36 - 0.87)
  
  
  CONCLUSIONS
  In addition to individual factors such as comorbidity, other factors such as educational level, ethnicity or overcrowding were associated with hospitalization due to A (H1N1) 2009 influenza virus infections.
authors: Servicio de Vigilancia epidemiológica de Andalucia, Sevilla, Spain. josem.mayoral.sspa@juntadeandalucia.es
authors: José María
authors: JM
authors: Mayoral
authors: Jordi
authors: J
authors: Alonso
authors: Olatz
authors: O
authors: Garín
authors: Zaida
authors: Z
authors: Herrador
authors: Jenaro
authors: J
authors: Astray
authors: Maretva
authors: M
authors: Baricot
authors: Jesús
authors: J
authors: Castilla
authors: Rafael
authors: R
authors: Cantón
authors: Ady
authors: A
authors: Castro
authors: Miguel
authors: M
authors: Delgado-Rodríguez
authors: Alicia
authors: A
authors: Ferri
authors: Pere
authors: P
authors: Godoy
authors: Fernando
authors: F
authors: Gónzález-Candelas
authors: Vicente
authors: V
authors: Martín
authors: Tomás
authors: T
authors: Pumarola
authors: José María
authors: JM
authors: Quintana
authors: Núria
authors: N
authors: Soldevila
authors: Sonia
authors: S
authors: Tamames
authors: Angela
authors: A
authors: Domínguez
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D015986:Confounding Factors, Epidemiologic; D005260:Female; D054624:Health Status Disparities; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D008297:Male; D008403:Mass Screening; D016273:Occupational Exposure; D058873:Pandemics / Q000706:statistics & numerical data; D012923:Social Class; D013030:Spain / Q000453:epidemiology
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