Abstract
Background/Aims Screening decreases colorectal cancer incidence and mortaility. However, almost half of eligible adults are not screened at recommended intervals. SOS: Systems of Support to Increase Colorectal Cancer Screening and Follow-up (R01CA121125) is a 4-arm randomized controlled trial that uses a systems-based approach to increase CRCS. We describe characteristics of patients who were not up-to-date compared to those current for CRCS and those who refused to participate in the study.
Methods The setting was 21 primary care clinics at Group Health, in the Pacific Northwest. Between 2008 and 2009, automated databases were used to identify patients age 50–73 with no life-threatening diseases. We used automated data to ascertain their prior CRCS status. Those not up-to-date were called to confirm their eligibility and willingness to participate in the trial. We collected automated and survey data to determine covariates related to not being up-to-date and refusing participation.
Results Based on automated data alone, 54.4% (28,508/52,556) of age-eligible patients were not up-to-date for CRCS. Those not up-to-date were younger, had fewer preventive care visits and screening tests for other cancers, lower levels of expected clinical need (a co-morbidity score), and less continuity of care with one physician. Patients not up-to-date for CRCS were randomly selected (n=15,451) to receive recruitment letters and telephone calls to confirm eligibility. Patients refusing to participate (N=6646) were younger, had lower levels of education, were more often from minority racial or ethnic groups, on Medicaid, and had fewer preventive care visits and other cancer screening tests than those who enrolled. They also more frequently reported they had never had any type of CRCS compared to participants (60.9% vs. 46%, P=<.001).
Conclusion Similar to other studies, patients not up-to-date for CRCS are more often from underserved groups and get less preventive and cancer screening care. Unfortunately, these same factors are associated with refusal to participate in a trial to increase CRCS. Studies requiring verbal informed consent will have a hard time testing the effectiveness of interventions to increase CRCS for those most needing it.
