[Alimentary factors and gastric cancer: design of a hospital based case-control study]

One of the most widely used design in etiologic research is the case-control study. In the present work the methodology used in the design of a case-control study, performed in a hospital setting, which objectives was to verify etiological hypothesis related with food-intake and gastric adenocarcinoma and 234 controls from the population--188 selected through a randomized selection on the phone book and 46 following neighborhood criteria--are studied. The methodology and the development of the field work are described, with a special interest in the possible bias incurred during its design and development.