Cologuard: test sensitivity is the start of a screening pathway

Clarus Biotech Review

The 2014 record connects a diagnostic metric to false positives, follow-up, and completed care.

Cologuard provides a specific diagnostic milestone example. The 2014 pivotal study evaluated 9,989 participants and compared multitarget stool DNA testing with fecal immunochemical testing, using colonoscopy as the reference. Colorectal-cancer sensitivity was 92.3% for stool DNA and 73.8% for FIT. [1]

## Pair sensitivity with the correct specificity

Among participants with nonadvanced or negative findings, specificity was 86.6% for stool DNA and 94.9% for FIT. These figures refer to that denominator, not only to participants with a completely negative colonoscopy. A headline that reports sensitivity alone omits the downstream work associated with positive tests. [1]

## Regulatory use defines the next step

FDA's original August 11, 2014 approval described the stool-based screening use and stated that a positive result should be followed by diagnostic colonoscopy. The test therefore participates in a care pathway; a completed kit is not a completed diagnosis. Later labels and newer versions must be considered separately from this historical record. [2]

## Adoption needs a second denominator

For implementation, count ordered kits, returned usable samples, communicated results, positive tests with completed follow-up, and the interval to that follow-up. Technical performance in a pivotal cohort does not establish those routine-care completion rates. A health system also needs a plan for an inaccessible next step, including referral capacity and patient support.

## Value inflection comes from an actionable service

A diagnostic business case should include repeat kits, laboratory processing, outreach, false-positive follow-up, and the care setting's actual costs. The pivotal sensitivity estimate is an important result but not a complete health-economic conclusion. An integrated milestone joins analytical reliability, clinical performance, and a measurable pathway to the decision the test is intended to support.

Source adaptation: BioClarus's diagnostic milestone paper supplies the validation-to-adoption lens. The article now uses colorectal screening as its distinct public case, rather than repeating the general diagnostic framework.

Sources

https://pubmed.ncbi.nlm.nih.gov/24645800/

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm?id=P130017

Original article: https://www.clarusreview.bio/articles/diagnostic-value-inflection-evidence-to-adoption