Social class based on occupation is associated with hospitalization for A(H1N1)pdm09 infection. Comparison between hospitalized and ambulatory cases

• Published in: Epidemiology and infection Vol. 144; no. 4; pp. 732 - 740
• Main Authors: PUJOL, J., GODOY, P., SOLDEVILA, N., CASTILLA, J., GONZÁLEZ-CANDELAS, F., MAYORAL, J. M., ASTRAY, J., GARCIA, S., MARTIN, V., TAMAMES, S., DELGADO, M., DOMÍNGUEZ, A.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01-03-2016
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Chronic obstructive pulmonary disease; Classification; Epidemiology; Female; Hospitalization; Hospitalization - statistics & numerical data; Hospitals; Humans; Immunization; Infectious diseases; Influenza; Influenza A Virus, H1N1 Subtype - physiology; Influenza, Human - epidemiology; Influenza, Human - virology; Male; Manual workers; Middle Aged; Nosocomial infections; Occupations; Original Papers; Pandemics; Prevalence; Professions; Public health; Risk Factors; Seasons; Social Class; Social classes; Sociodemographics; Spain - epidemiology; Vaccines; Variables; Working groups; Young Adult; Spain; United States > US; California; vaccination (immunization); Influenza A; outbreaks; public health emerging infections; public health
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268815001892

This study aimed to analyse the existence of an association between social class (categorized by type of occupation) and the occurrence of A(H1N1)pmd09 infection and hospitalization for two seasons (2009–2010 and 2010–2011). This multicentre study compared ambulatory A(H1N1)pmd09 confirmed cases with ambulatory controls to measure risk of infection, and with hospitalized A(H1N1)pmd09 confirmed cases to asses hospitalization risk. Study variables were: age, marital status, tobacco and alcohol use, pregnancy, chronic obstructive pulmonary disease, chronic respiratory failure, cardiovascular disease, diabetes, chronic liver disease, body mass index >40, systemic corticosteroid treatment and influenza vaccination status. Occupation was registered literally and coded into manual and non-manual worker occupational social class groups. A conditional logistic regression analysis was performed. There were 720 hospitalized cases, 996 ambulatory cases and 1062 ambulatory controls included in the study. No relationship between occupational social class and A(H1N1)pmd09 infection was found [adjusted odds ratio (aOR) 0·97, 95% confidence interval (CI) 0·74–1·27], but an association (aOR 1·53, 95% CI 1·01–2·31) between occupational class and hospitalization for A(H1N1)pmd09 was observed. Influenza vaccination was a protective factor for A(H1N1)pmd09 infection (aOR 0·41, 95% CI 0·23–0·73) but not for hospitalization. We conclude that manual workers have the highest risk of hospitalization when infected by influenza than other occupations but they do not have a different probability of being infected by influenza.