Trial Information

Initiation of Colon Cancer Screening in Veterans

Colorectal cancer (CRC) is the 2nd leading cause of cancer deaths in the US and risk
increases with age. Colorectal cancer screening (CRCS) offers the possibility of both early
detection and prevention. For those at average risk, CRCS beginning at age 50 is
recommended. However, awareness and use of CRCS tests are low. We propose to conduct a
randomized controlled trial to develop and test stepped interventions to increase initial
uptake of CRCS in a nationally-representative, ethnically-diverse sample of male and female
veterans. Our specific aims are to: (1) develop and pre-test stepped intervention components
that are theory and evidence-informed; (2) implement and evaluate the process, efficacy, and
cost-effectiveness of stepped interventions to increase an initial CRCS among male and
female veterans aged 50-64 years; and (3) analyze the association between predictor
variables and CRCS initiation and the mediating and moderating effects of the interventions,
after each step. In Step 1, we will evaluate a theory-based minimal cue delivered by a
letter, telephone call, or automated telephone call compared with a survey-only control
group to determine whether the 3 different delivery channels are equally efficacious and
cost-effective. Minimal cues are a cost-effective method that prompts to action those more
willing to change and are easy to disseminate in real-world settings. Persons who do not
complete CRCS in Step 1 will be randomized in Step 2 to more intensive interventions that
address resistance. In Step 2 we will determine whether a theory-based, tailored telephone
intervention, using principles of Motivation Interviewing, is effective when delivered as
part of a sequential intervention process in which early adopters have been removed from the
population. Step 2 also will determine whether an automated approach, telephone-linked
communication (TLC), is as effective as a telephone counselor in promoting initiation of
CRCS. Steps 1 and 2 together will address the important issue of the "dose" needed to
encourage completion of CRCS. After each step, we will examine the mediating and moderating
effects of the intervention to identify determinants of completion. For cancer screening
intervention research to have the broadest public health impact, interventions must have the
potential for dissemination. We designed our trial to move us toward the goal of
disseminable interventions with evidence of external validity.