Adherence to Competing Strategies for Colorectal Cancer Screening Over 3 Years

Abstract

Objectives We have shown that, in a randomized trial comparing adherence to different colorectal cancer (CRC) screening strategies, participants assigned to either fecal occult blood testing (FOBT) or given a choice between FOBT and colonoscopy had significantly higher adherence than those assigned to colonoscopy during the first year. However, how adherence to screening changes over time is unknown. Methods In this trial, 997 participants were cluster randomized to one of the three screening strategies: (i) FOBT, (ii) colonoscopy, or (iii) a choice between FOBT and colonoscopy. Research assistants helped participants to complete testing only in the first year. Adherence to screening was defined as completion of three FOBT cards in each of 3 years after enrollment or completion of colonoscopy within the first year of enrollment. The primary outcome was adherence to assigned strategy over 3 years. Additional outcomes included identification of sociodemographic factors associated with adherence. Results Participants assigned to annual FOBT completed screening at a significantly lower rate over 3 years (14%) than those assigned to colonoscopy (38%, P<0.001) or choice (42%, P<0.001); however, completion of any screening test fell precipitously, indicating the strong effect of patient navigation. In multivariable logistic regression analysis, being randomized to the choice or colonoscopy group, Chinese language, homosexuality, being married/partnered, and having a non-nurse practitioner primary care provider were independently associated with greater adherence to screening (P<0.01). Conclusions In a 3-year follow-up of a randomized trial comparing competing CRC screening strategies, participants offered a choice between FOBT and colonoscopy continued to have relatively high adherence, whereas adherence in the FOBT group fell significantly below that of the choice and colonoscopy groups. Patient navigation is crucial to achieving adherence to CRC screening, and FOBT is especially vulnerable because of the need for annual testing.

Comparative Effectiveness and Cost Effectiveness of a Multitarget Stool DNA Test to Screen for Colorectal Neoplasia

“…In threshold analyses, consistent and intermittent screening rates were varied in the same proportions first, and were varied separately only when specific thresholds were not achievable otherwise. Participation patterns have been described over the medium term, but not over 30 years; 5,6,12,13,16,17,21,[27][28][29][30][31][32] we extrapolated these patterns over the simulation's time horizon.…”

“…12,13 The population proportions in each group were based on published reports of screening programs and clinical trials, 5,6,12,13,16,17,21,[27][28][29][30][31][32] and these were varied to reflect different scenarios, including organized programs providing "patient support." In threshold analyses, consistent and intermittent screening rates were varied in the same proportions first, and were varied separately only when specific thresholds were not achievable otherwise.…”

Colorectal Cancer Screening: Recommendations for Physicians and Patients from the U.S. Multi-Society Task Force on Colorectal Cancer

“…FIT is commonly the test of choice in programmatic screening, an excellent second choice for practitioners using sequential testing who off er colonoscopy fi rst, and should likely always be one of the tests included in a multiple-options approach. Disadvantages of FIT include the need for repeated testing, which can be problematic in the nonprogrammatic (opportunistic) setting ( 13 ), and poor or no sensitivity for serrated class precursor lesions ( 53 ). However, there is no evidence that cancers arising through serrated class lesions are less likely to bleed than those arising via adenomas.…”

“…In the opportunistic setting there may not be resources allocated to systematically ensure that FIT-positive patients are referred for colonoscopy and that FIT-negative patients are off ered repeat testing or to monitor whether compliance with quality targets is adequate ( 13 ). Inability to allocate resources to monitor the quality of FIT testing is a factor favoring reliance on sequential testing with colonoscopy the fi rst test off ered.…”

“…Th e MSTF anticipates growth of programmatic screening within healthcare systems but expects at least short-term continued reliance on opportunistic screening in the United States. Reliance on opportunistic screening can aff ect the preference for CRC screening, because achieving compliance with tests that should be repeated at short intervals is more challenging in the opportunistic setting ( 13 ).…”