To identify patients at risk for nonattendance to their first scheduled colonoscopy and to conduct a randomized trial of a theory-based, peer coach intervention on completing the scheduled colonoscopy.

The potential to reduce the morbidity and mortality from colorectal cancer, the second most common cause of cancer death in the U.S. has been compromised because only about half of eligible patients have been appropriately screened. Patients contribute to inadequate colorectal cancer screening by failing to complete ordered tests. Several studies have reported low rates of attendance to scheduled sigmoidoscopy and colonoscopy studies. Because physicians offer limited counseling when ordering these tests, approaches are needed to address patient concerns and to promote adherence to scheduled colon studies. Therefore, we conducted a trial of a theory-based telephone intervention by patient 'peer coach' who was trained to address barriers to colonoscopy attendance versus a mailed professional brochure. The support was targeted to those at greatest risk of non-attendance.

Inclusion Criteria:

• Age 50
• No prior colonoscopy in our health system records
• Patient in one of four primary care clinics within the University of Pennsylvania Health System
• Attended <75 of their primary care physicians visits within the past year

Exclusion Criteria:

• Colonoscopy not ordered by a primary care physician in a study clinic
• High readiness for the procedure
• A health care professional
• Had a prior colonoscopy outside of our health care system