Systems of Support (SOS) to Increase Colon Cancer Screening and Follow-up Supplement

Ancillary Aim #1 We will evaluate intervention effects by comparing binary outcomes for
screening (yes/no) in the primary SOS study. In this aim, we propose to calculate actual
screening rates by use of time-to-event analyses (also known as survival analysis). The
outcome variable of interest is the first time since randomization to have CRCS, either based
on FOBT, FS, or CS. Knowing screening rates will not only enable us to make comparisons
between groups, but also over time.

Ancillary Aims #2 and #3 We will recruit additional participants for two ancillary study
aims. First, we will enroll patients age 50-74 years using the same criteria as for the
primary SOS study, which includes neither history of colorectal cancer nor evidence of
life-limiting disease. Participants who return the questionnaire, consent and considered
eligible will be randomized to receive one of three different at-home fecal test kits. The
kits will be returned to the GH centralized laboratory, and participants will be informed
about lab results using standard GH pathways. Participants who have a test-positive will
receive a series of two follow-up surveys (first at 1-2 weeks post result and second at
4-months post result). A comparison group of test-negative results will be matched based on
selected criteria, and this group will also receive the follow-up surveys. Participants at
both time intervals who do not return the survey via mail will be called and if available,
administered the questionnaire via phone.