Baseline Features and Reasons for Nonparticipation in the Colonoscopy Versus Fecal Immunochemical Test in Reducing Mortality From Colorectal Cancer (CONFIRM) Study, a Colorectal Cancer Screening Trial

Abstract

Importance: The Colonoscopy Versus Fecal Immunochemical Test in Reducing Mortality From Colorectal Cancer (CONFIRM) randomized clinical trial sought to recruit 50 000 adults into a study comparing colorectal cancer (CRC) mortality outcomes after randomization to either an annual fecal immunochemical test (FIT) or colonoscopy.

Objective: To (1) describe study participant characteristics and (2) examine who declined participation because of a preference for colonoscopy or stool testing (ie, fecal occult blood test [FOBT]/FIT) and assess that preference's association with geographic and temporal factors.

Design, setting, and participants: This cross-sectional study within CONFIRM, which completed enrollment through 46 Department of Veterans Affairs medical centers between May 22, 2012, and December 1, 2017, with follow-up planned through 2028, comprised veterans aged 50 to 75 years with an average CRC risk and due for screening. Data were analyzed between March 7 and December 5, 2022.

Exposure: Case report forms were used to capture enrolled participant data and reasons for declining participation among otherwise eligible individuals.

Main outcomes and measures: Descriptive statistics were used to characterize the cohort overall and by intervention. Among individuals declining participation, logistic regression was used to compare preference for FOBT/FIT or colonoscopy by recruitment region and year.

Results: A total of 50 126 participants were recruited (mean [SD] age, 59.1 [6.9] years; 46 618 [93.0%] male and 3508 [7.0%] female). The cohort was racially and ethnically diverse, with 748 (1.5%) identifying as Asian, 12 021 (24.0%) as Black, 415 (0.8%) as Native American or Alaska Native, 34 629 (69.1%) as White, and 1877 (3.7%) as other race, including multiracial; and 5734 (11.4%) as having Hispanic ethnicity. Of the 11 109 eligible individuals who declined participation (18.0%), 4824 (43.4%) declined due to a stated preference for a specific screening test, with FOBT/FIT being the most preferred method (2820 [58.5%]) vs colonoscopy (1958 [40.6%]; P < .001) or other screening tests (46 [1.0%] P < .001). Preference for FOBT/FIT was strongest in the West (963 of 1472 [65.4%]) and modest elsewhere, ranging from 199 of 371 (53.6%) in the Northeast to 884 of 1543 (57.3%) in the Midwest (P = .001). Adjusting for region, the preference for FOBT/FIT increased by 19% per recruitment year (odds ratio, 1.19; 95% CI, 1.14-1.25).

Conclusions and relevance: In this cross-sectional analysis of veterans choosing nonenrollment in the CONFIRM study, those who declined participation more often preferred FOBT or FIT over colonoscopy. This preference increased over time and was strongest in the western US and may provide insight into trends in CRC screening preferences.

Conflict of interest statement

Conflict of Interest Disclosures: Dr Robertson reported receiving advisory board fees from Freenome outside the submitted work. Dr Gupta reported receiving research support from Freenome and Epigenomics and consulting fees from Guardant Health, Geneoscopy, and InterVenn Bioscience outside the submitted work. Dr Lieberman reported receiving consulting fees from Geneoscopy outside the submitted work. Drs Schoenfeld and Antaki and Dr S. Ho reported receiving grants from the Department of Veterans Affairs (VA) during the conduct of the study. Drs Pedrosa, Kinnard, and Dunbar reported receiving grants from the VA Cooperative Study Program during the conduct of the study. Dr Sullivan reported receiving grants from Exact Sciences outside the submitted work. Dr Kohli reported receiving grants from Olympus Corporation of the Americas paid to his institution, standards of practice committee membership with the American Society for Gastrointestinal Endoscopy, and governance board membership with the American Board of Internal Medicine outside the submitted work. Prof Sharma reported receiving consulting fees from Olympus Corporation, Boston Scientific, Salix Pharmaceuticals, Cipla, Medtronic, Takeda, Samsung Bioepis, and CDx and grants from Erbe and Fujifilm outside the submitted work. Dr May reported receiving personal fees from Exact Sciences and Freenome outside the submitted work. Dr Pisegna reported receiving personal fees from AbbVie outside the submitted work. Dr Pohl reported receiving grants from Steris and Cosmo Pharmaceuticals and consulting fees from InterVenn Bioscience outside the submitted work. No other disclosures were reported.

Figures

Figure 1.. Flow Diagram Describing the Screened, Enrolled, and Randomized Colonoscopy Versus Fecal Immunochemical Test in Reducing Mortality From Colorectal Cancer Population

FIT indicates fecal immunochemical testing.

Figure 2.. Individuals Eligible for Participation Who Declined Because of a Stated Preference for Stool Testing With Fecal Occult Blood Test or Fecal Immunochemical Test vs Colonoscopy, Stratified by Region and Year of Attempted Recruitment