Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Med Screen. 2008;15(1):18-22. doi: 10.1258/jms.2008.007076.

Estimating the cumulative risk of a false-positive under a regimen involving various types of cancer screening tests.

Author information

  • 1Division of Cancer Prevention, National Cancer Institute, 6130 Executive Blvd. MSC 7354, Bethesda, MD 20892-7354, USA. sb16@nih.gov

Abstract

OBJECTIVES:

When evaluating screening for the early detection of cancer, it is important to estimate both harms and benefits. One common harm is a false-positive (FP), which is a positive screening result, perhaps followed by an invasive test, with no cancer detected on the diagnostic work-up or within a specified time period. An important goal is to estimate the risk of at least one FP, which we call the cumulative risk of an FP, if persons took a regimen of various screening tests, as is commonly recommended. The estimation is complicated because the data come from a study in which subjects are offered various screening tests in rounds with some missing tests in most subjects. Previous methods for estimating cumulative risk of FPs with a single type of test are not directly applicable, so a new approach was developed.

METHODS:

The tests were ordered by appearance, where the last test was either the first FP (analogous to a failure time) or the last test taken with no FPs having occurred on that test or previously (analogous to a censoring time). We applied a Kaplan-Meier approach for survival analysis with the innovation that the hazard for a first FP for a given test depends on the type of test and number of previous tests of that type which were taken.

RESULTS:

The method is illustrated with data from the screening arm of the randomized Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. With an FP defined as a diagnostic work-up in the absence of cancer (or advanced adenoma) within three years, the probability of at least one FP among 14 tests in men was 60.5% with 95% confidence interval of (59.3%, 61.6%).

CONCLUSION:

A simple estimate is proposed for the probability of at least one FP if persons took a regimen of multiple screening tests of different types. The methodology is useful for summarizing the burden of multiphasic screening programmes.

PMID:
18416950
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk