A Critical Look at Prevention: Colorectal Cancer Screening

Abstract

This preventive medicine teaching case, part of the Cases in Population-Oriented Prevention series, discusses the concepts of diagnostic test evaluation, prevention, and screening using the example of colorectal cancer screening. Features of the case include a health policy exercise concerning community screening programs and an exercise in clinical prevention decision-making.

Objectives:

• Calculate the characteristics of diagnostic tests: sensitivity, specificity and positive and negative predictive values
• Evaluate screening tests in terms of their validity, results and generalizability
• Employ the concepts of primary and secondary prevention as they relate to common clinical preventive services
• Describe the appropriate conditions for screening in terms of characteristics of the disease, the patient and the screening test
• Describe the appropriate study design to evaluate the effectiveness of a screening program and discuss the common biases encountered in screening program research
• Evaluate locally obtained survey data about screening rates and attitudes and devise a community response to increase colorectal cancer screening