Epidemiology and its applications for geriatrics and gerontology in Brazil

The population of developing countries is ageing rapidly, bringing new challenges for public health. In developing countries, the growth of the aged population occurs in environment of poverty and great social inequality. In such environment, risk exposures and diseases are more frequent and, on the other hand, the resources for treatment and rehabilitation are scarce. The epidemiology plays a central role for public health. Epidemiologic studies provide scientific evidences that are essential for subsidizing polices toward the elderly health. In this paper, some types of epidemiological studies are described (ecological, cross-sectional, case-control and cohort studies), as well as some of their uses. Among the uses of epidemiology, the following were considered: (a) surveillance; (b) health survey; (c) validity and reliability of diagnostic tests; (d) natural history of diseases; (e) causes of diseases; (f) evaluation of effectiveness. We used data from a long term Brazilian cohort study of older adults (the Bambui study), as well as data from public hospitalizations in Brazil as examples. The results of these studies are examples of the usefulness of the epidemiology to investigate the distribution of health-related conditions in the aged population, as well as their determinants.