Open Access Research article

Influence of socioeconomic status on community-acquired pneumonia outcomes in elderly patients requiring hospitalization: a multicenter observational study

Conchita Izquierdo1*, Manuel Oviedo23, Laura Ruiz13, Xavier Sintes4, Isabel Vera5, Manel Nebot34, Jose-María Bayas5, Jordi Carratalà6, Wenceslao Varona7, Dolores Sousa8, Jose-Miguel Celorrio9, Luis Salleras103, Angela Domínguez103 and Working Group for the Study of the Prevention of CAP in the Elderly

Author Affiliations

1 Department of Health, Generalitat of Catalonia, Roc Boronat 81-95, 08005 Barcelona, Spain

2 Department of Statistics and Operative Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain

3 CIBER Epidemiología y Salud Pública (CIBERESP) Dr Aiguader 88, 08003 Barcelona, Spain

4 Public Health Agency of Barcelona, Pl Lesseps 1, 08023 Barcelona, Spain

5 Hospital Clínic, Department of Preventive Medicine and Epidemiology, Calle Villarroel 170, 08036 Barcelona, Spain

6 Bellvitge University Hospital-IDIBELL, Department of Infectious Diseases, University of Barcelona, C/Feixa Llarga S/N 08907 L'Hospitalet de LLobregat, Barcelona, Spain

7 Hospital Royo Villanova, Department of Preventive Medicine, San Gregorio 30, 50015 Zaragoza, Spain

8 Hospital Juan Canalejo, Department of Infectious Diseases, As Xubias, número 84, 15006 A Coruña, Spain

9 Hospital Ernest Lluch, Department of Preventive Medicine, ctra. Sagunto-Burgos Km 254, 50300 Calatayud, Spain

10 Department of Public Health, University of Barcelona, C/Casanova 143, 08036 Barcelona, Spain

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BMC Public Health 2010, 10:421  doi:10.1186/1471-2458-10-421

Published: 15 July 2010



The associations between socioeconomic status and community-acquired pneumonia outcomes in adults have been studied although studies did not always document a relationship.

The aim of this multicenter observational study was to determine the association between socioeconomic status and community-acquired pneumonia outcomes in the elderly, in the context of a public health system providing universal free care to the whole population.


A total of 651 patients aged ≥65 years hospitalized due to community-acquired pneumonia through the emergency departments of five Spanish public hospitals were recruited and followed up between May 2005 and January 2007. The primary outcomes studied were: length of stay, intensive care unit admission, overall mortality and readmission. Socioeconomic status was measured using both individual and community data: occupation [categorized in six social groups (I, II, III, IVa, IVb and V)], educational level (≤ primary level or ≥ secondary level) and disposable family income of the municipality or district of residence [>12,500 € (high municipality family income) and ≤12,500 € (low municipality family income)]. The six social groups were further categorized as upper/middle social class (groups I-IVb) and lower class (group V).

Bivariate and multivariate analyses were performed. OR and their 95% confidence intervals were calculated. All statistical tests were two tailed and statistical significance was established as p < 0.05.


17.7% of patients lived in a municipality or district with a high municipality family income and 63.6% were upper/middle social class (I-IVb). Only 15.7% of patients had a secondary education. The adjusted analysis showed no association between pneumonia outcomes and social class, educational level or municipality family income. However, length of stay increased significantly in patients in whom the factors, living alone and being a smoker or ex-smoker coincided (p < 0.001).


We measured socioeconomic status using both individual and community data and found no association between social class, educational level or municipality family income and the variables of pneumonia outcomes. The lack of differences between social classes supports the provision of universal, equitable health care by the public health system.