Social factors related to the clinical severity of influenza cases in Spain during the A (H1N1) 2009 virus pandemic

Mayoral, José María; Alonso Caballero, Jordi; Garin Boronat, Olatz, 1979-; Herrador, Zaida; Astray, Jenaro; Baricot, Maretva; Castilla, Jesús; Cantón, Rafael; Castro, Ady; Delgado Rodríguez, Miguel; Ferri, Alicia; Godoy i García, Pere; González Candela, Fernando; Martín, Vicente; Pumarola, Tomás; Quintana, José María; Soldevila, Núria; Tramames, Sonia; Domínguez García, Àngela; CIBERESP Cases and Controls in Pandemic Influenza Working Group

doi:http://dx.doi.org/10.1186/1471-2458-13-118

Social factors related to the clinical severity of influenza cases in Spain during the A (H1N1) 2009 virus pandemic

Citation

Mayoral JM, Alonso J, Garin O, Herrador Z, Astray J, Baricot M et al. Social factors related to the clinical severity of influenza cases in Spain during the A (H1N1) 2009 virus pandemic. BMC Public Health. 2013; 13: 118. DOI 10.1186/1471-2458-13-118

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.