PREVALENCE OF CANCER IN THE ELDERLY - DISCREPANCIES BETWEEN SELF-REPORTED AND REGISTRY DATA

In both large cohort and genetic studies, the absence of a population based cancer register for convenient identification of individuals wit h cancer often means that self-reported data are used. In such cases, only positive responses tend to be verified. However, relatively littl e attention has been focused on the real possibility of significant nu mbers of false-negative responses. In view of the high incidence of ca ncer in the elderly (Yancik and Ries, 1994; Coleman and Lutz, 1996), a n increasing number of elderly people are likely to be included in fut ure epidemiological studies. These considerations prompted us to exami ne the validity of information reported by a population of elderly per sons with respect to the occurrence of cancer. Data from a cross-secti onal epidemiological survey carried out in the French department of th e Tarn (SW France) were cross-checked against data from a cancer regis try of the same department used as reference.