Collecting Health Outcomes and Economic Data on Hospitalized Community-Acquired Pneumonia - a Prospective Cohort Study

Within the study data on quality of life and various health and non-health resources and their costs is collected with the help of questionnaires administered at different points in time in different cohorts. Data collection is additional upon data collected in the main CAPITA trial, such as incidence data, mortality estimates, use of some health care resources, vaccine effectiveness and general background (socio-demographic) data.

In a first sub-study of CHO-CAP, the CAPITA participants are asked, via written information distributed shortly after vaccination, to fill in once-only a short questionnaire describing their health status (5 item EQ-5D instrument) and a few additional socio-demographic background data. This is done in order to determine an EQ-5D baseline score (index value for health status) - a prerequisite to match CAP patients and controls later, and as such an inclusion criterion for the two (nested) cohorts that will be followed prospectively.

About 2,000 cases of CAP are expected to occur in the CAPITA cohort in the next two to three years. Assuming a response rate of ~30% for the baseline questionnaire, we will have some 600 CAP cases out of the 2,000 expected patients for whom a baseline EQ-5D score is available. These CAP patients will be asked to participate in a prospective cohort study. Within CHO-CAP, these CAP cases will be followed for up to one year after their CAP episode. For each CAP case included in the CAP cohort, two controls from the baseline population are matched and included in a cohort of controls (non-CAP elderly with similar baseline health status). Controls will also be followed for up to one year. The matches between CAP cases and controls will be made based on age, sex and EQ-5D baseline score. This implies that controls will only be recruited from the group that responded to the baseline measurement of health status shortly after vaccination. For both cohorts, the CAP patients and the matched controls, additional data on health care and non-health care resource use, on health status, using EQ-5D and SF-36 questionnaires, and on selected health outcomes is collected at four contact (at 0, 1, 6 and 12 months) moments within a period of 1 year. This will be done using questionnaires, distributed during a home visit and by post.