title: Statistical issues in the evaluation of screening and early detection modalities.
abstract: Thorough evaluation of a screening test requires conducting a series of studies to ascertain its ability to detect accurately disease, as well as its benefits and costs. In this article, I review the steps involved in evaluating a screening test, using the case of prostate-specific antigen (PSA) screening for prostate cancer as a case study. I discuss designs for quantifying the diagnostic properties of a screening test and compare several different studies that have produced quite different estimates of the diagnostic accuracy of PSA screening. I also review methods that may be used to combine other markers or tests with PSA to improve test accuracy. Determining the benefits of a screening test is complex, particularly when information from randomized trials is lacking. I review several observational studies of PSA benefit and discuss the use of computer models for inferring the impact of screening from trends in population mortality.
authors.affiliation: Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA. retztioni@fhcrc.org
authors.forename: Ruth
authors.initials: R
authors.lastname: Etzioni
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood; D005189:False Positive Reactions; D006801:Humans; D008403:Mass Screening / Q000191:economics / Q000379:methods* / Q000706:statistics & numerical data*; D012372:ROC Curve; D013997:Time Factors
chemical_list: D014408:Biomarkers, Tumor