Hospitalization by pneumonia and influenza in the 50-64 year old population in Spain (1999-2002).

This epidemiological survey was undertaken to estimate the burden of hospital admissions for pneumonia and influenza in 50-64 years old persons in Spain during a four-year period (1999-2002). Data were obtained from the national surveillance system for hospital data maintained by the Ministry of Health and covering more than 95% of Spanish hospitals. There were 35,620 hospital admissions for pneumonia and influenza (ICD 9 CM 480-487; first listed diagnosis) during the study period.