Screening: why, when, and how

Screening refers to the early detection of individuals with unrecognized disease or with early stages of disease among a population. Early detection allows early medical intervention, which may ultimately slow progression of the disease and reduce both morbidity and mortality. As such, screening is an important tool in improving public health. In 1968, Wilson and Jungner proposed 10 criteria to consider prior to starting screening for a disease. This review discusses these criteria when applied to screening for chronic kidney disease with additional focus on (1) the validity of the test to be used for screening; (2) which part of the population to screen; and (3) forms of bias to consider in screening.