The incidence rate of familial adenomatous polyposis. Results from the Danish Polyposis Register.

and increasing bias due to the significant improval of the prognosis of familial adenomatous polyposis during the last decades. Moreover, most studies are not based on epidemiologically valid patient series without selection bias. Recent calculations of the incidence rate with a direct method have been published on the basis of the national Danish and Finnish polyposis series, showing an annual incidence rate of 1.3 ‐ 1.6〈10 ‐6 in the early 1980’s [5, 6]. The aim of the present study was to reevaluate the occurrence of the disease about 25 years after the establishment of the Danish Polyposis Register by presenting estimates on the incidence rate, the point prevalence rate, and the completeness of registration.