Self-reported information on the diagnosis of colorectal cancer was reliable but not necessarily valid

Abstract

Objective: Self-report is commonly used in epidemiologic studies; however, few data exist on the reliability and validity of this method for eliciting information related to the diagnosis of colorectal cancer. We examined the test-retest reliability and validity of colorectal cancer patients reporting on the process of their diagnosis. Study Design and Setting: One hundred and sixteen participants completed two telephone interviews, 1 month apart, and 95 general practitioners (GPs) completed a written questionnaire, to elicit information relating to key elements of the process of diagnosis of colorectal cancer. Results: Acute symptoms such as rectal bleeding had higher reliability and validi..