Estimating the influence of rescreening interval on the benefits associated with cancer screening: approaches and limitations.

ABSTRACT Randomized controlled trials that seek to measure the ability of a screening test to lower cancer mortality generally do not provide data that bear on the relative efficacy of different screening intervals. Guidance regarding the choice of a screening interval that achieves a high level of case-finding, without being excessively costly, can be obtained from one or more of several study designs that examine the subsequent occurrence of cancer in persons who have had a negative screening test. However, each of these can potentially provide a misleading result, and so their limitations must be considered before using the data they generate to develop a rational rescreening policy.