National Colonoscopy Study flowchart by screening round
Screening colonoscopy (SCO), High sensitivity guaiac fecal occult blood test (HSgFOBT)
1, 2, 3, 4: Had a colonoscopy and later went on to participate in more screening in some form (i.e. did not discontinue forever), n = 10, 6, 5, 2, respectively
5: 1 patient crossed over in round 4. They did not receive an FOBT kit in round 4.