The prospective cohort study will evaluate the effectiveness of patient navigation in community health center settings. The investigators will collaborate with the advisory board, composed of key clinicians and patients, researchers, and policymakers, to establish a procedure to conduct and evaluate a patient navigation program that aims to increase rates of follow-up colonoscopy among diverse patient populations served by safety net clinics. Phase 1 will be a milestone-driven planning process in which the investigators will validate the risk prediction model and apply the risk prediction model to stratify the patients and adapt patient navigation materials for the local context. Phase II will be a large-scale, patient randomized-controlled trial that will include 1200 patients at a large 34-clinic community health center in Washington State.

The study will fulfill the following aims:

Aim 1: Validate externally the predictive risk score using Sea Mar CHC's robust data including 29,000 patients age-eligible for colorectal cancer screening; stratify patients according to risk of non-adherence to follow-up colonoscopy; and adapt patient navigation program for the local context.

Aim 2: Assess the effectiveness, costs, and cost-effectiveness of a centralized, phone-based patient navigation program for follow-up colonoscopy receipt for patients at moderate risk or high risk for non-adherence.

Aim 3: Assess differences in the intervention arms in secondary outcomes (e.g. time to colonoscopy receipt, no-show/canceled appointments, colonoscopy quality) and moderators of intervention effectiveness (e.g. probability level, intervention dose, and patient age, ethnicity, and sex)

Inclusion Criteria:

• Positive FIT test

Exclusion Criteria:

• Prior colorectal cancer
• Dialysis patient