Use of active patient follow-up in cancer registries for designing epidemiologic studies.

The two primary functions of a population-based cancer registry are to collect incidence data and survival data, often obtained by active contact methods. Because of the expense and complexities of epidemiological research in determining carcinogenic risk, existing aggregate data collection systems need to be utilized for generating hypotheses. Direct follow-up contact with a patient by mail provides a mechanism for identifying potential risk factors at low cost. This method is being used to solicit information concerning environmental exposure. In addition, analysis of preliminary data on education and occupation collected by the mechanism indicated that staying patterns of cancer differ between rural and urban areas in the state of Iowa. The difference appears to be explained by education and not by occupation.