Planning and execution of a multicentre case–control study to evaluate the effectiveness of the influenza and pneumococcal vaccines in the elderly

The aim of the study was to describe and evaluate the implementation, coordination, and management strategies used during the course of a multicentre case–control study in order to investigate the effectiveness of the influenza and pneumococcal vaccines in the prevention of hospital admissions due to influenza and pneumonia in patients aged 65 years and over during two influenza seasons in Spain. The project working group was composed of three...