Repeated testing. An overview and analysis.

Abstract

Physicians often obtain the same test over and over again. This article first considers screening tests, such as mammographic screening for breast cancer, and describes several proposals for finding the interval that best balances cost, harms, and benefits. The same principles apply to monitoring a patient for recurrence of a disease, such as bladder cancer. The article closes with a theoretical consideration of the circumstances for repeating a test once to check a surprising value.