Validation of Self-Reported Cancer Incidence at Follow-up in a Prospective Cohort Study

Abstract

Self-reported cancer is a valuable epidemiological tool for identifying cases in cohort studies. The cost, time, and resources required, in addition to the efficiency in ascertaining cases, need to be considered when deciding between active and passive follow-up approaches. Because Korean families hold a family-centered approach when making decisions (1), it is not uncommon for patients to be unaware of their cancer diagnosis or status. A total of 20% of physicians and 33% of family members opposed patient notification of his or her disease status (2), and only 35% of Korean-Americans would tell a patient about a terminal prognosis (1). Because of these cultural differences and, thus, inaccuracies in self-reported information that arise, there is a need to examine the appropriateness of the active follow-up approach in ascertaining incident cancer cases. The objectives of the study were to assess the validity and reliability of self-reported cancer at follow-up and to examine the relative efficiencies of the active and passive follow-up methods in identifying incident cancer cases.