Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

FIT Performance & Optimal Positivity Thresholds

Ann Intern Med; ePub 2018 Sep 18; Selby, et al

Among adults screened for colorectal cancer (CRC) using the fecal immunochemical test (FIT), increased cancer detection at lower positivity thresholds was counterbalanced by substantial increases in positive tests, indicating that tailored thresholds may provide screening benefits. The community-based cohort study included adults aged 50-75 years who were eligible for screening and had baseline quantitative FIT results (2013 and 2014) and 2 years of follow-up. Nearly two-thirds of participants (n=411,241) had FIT screening in the previous 2 years. Measurements included FIT programmatic sensitivity for CRC and number of positive test results per cancer case detected, overall, and by age and sex. Researchers found:

  • Of 640,859 persons who completed a baseline FIT and were followed for 2 years, 481,817 (75%) had at least 1 additional FIT and 1,245 (0.19%) received a CRC diagnosis.
  • Cancer detection increased at lower positivity thresholds; the number of positive test results per cancer case detected also increased.
  • Reducing the positivity threshold from 20 to 15 µg/g would detect 3% more cancer cases and require 23% more colonoscopies.


Selby K, Jensen CD, Lee JK, et al. Influence of varying quantitative fecal immunochemical test positivity thresholds on colorectal cancer detection: A community-based cohort study. [Published online ahead of print September 18, 2018]. Ann Intern Med. doi:10.7326/M18-0244.

This Week's Must Reads

Acute Illness and Cannabis Use in Adults, Ann Intern Med; ePub 2019 Mar 26; Monte, et al

Pregnancy History and Risk of Miscarriage, BMJ; ePub 2019 Mar 20; Magnus, et al

Firearms Mortality Among US Schoolchildren, Am J Med; ePub 2019 Mar 25; Rubenstein, et al

Rapid Point of Care Test for Influenza, J Am Board Fam Med; 2019 Mar; Dale, et al

Sleep Disturbance and Chronic Pain Intensity, Clin J Pain; ePub 2019 Mar 25; Burgess, et al

Must Reads in Oncology

Consumption of SSBs & Risk of Mortality, Circulation; ePub 2019 Mar 18; Malik, et al

Ultrasonography Screening in Breast Cancer, JAMA Intern Med; ePub 2019 Mar 18; Lee, et al

Do Vitamin D Supplements Prevent Cancer, CVD?, N Engl J Med; 2019 Jan 3; Manson, Cook, et al

Nonadherence to Cancer Screenings & Related Mortality, JAMA Intern Med; ePub 2018 Dec 28; Pierre-Victor, et al

Does Vitamin D Reduce Cancer & CVD Risk?, N Engl J Med; ePub 2018 Nov 10; Manson, et al