neighborhood control
a group of individuals selected from the same region or area as that of a targeted study group in order to serve as a comparison group. The assumption is that such a group will share similar experiences, risk exposure, and other relevant characteristics with the study group, given their geographical proximity. Used in epidemiological or clinical research, neighborhood controls generally are chosen according to some rule-based procedure and matched to members of the target group on certain attributes, such as age or sex. For example, a researcher investigating cancer might go to every second house on the same city block as that of each person in the study group to identify similar individuals who do not have the disease to become part of a neighborhood control. Also called community control.