Frequency and Co-occurrence of Younger Age and CRC Screening Barriers: A Systematic Review and Bibliometric Analysis

Introduction: In response to increasing colorectal cancer (CRC) incidence rates in younger adults, the USPSTF recently lowered the recommended age to initiate CRC screening from 50 to 45 years. However, national studies show lower CRC screening uptake in younger compared to older age groups, and the newly eligible 45-49 year age group may behave similarly. To better understand CRC screening challenges in younger age groups, we explored screening barriers identified from a systematic literature review (SLR) and used a co-occurrence network to describe patient- and provider-level barriers frequently co-occurring with younger age. Methods: The SLR identified CRC screening adherence studies in average-risk adults in the U.S. PubMed, Embase, and CENTRAL trial databases were searched on 10/23/2020 for articles published from 01/01/1950-12/31/2020. Eligible studies examined adherence to endoscopy or stool test screening guidelines and reported predictors of screening or described age-specific barriers. Iterative thematic coding on extracted data resulted in 71 patient- and 16 provider-level factors. This analysis focused on the subset of studies defining adherence as up-to-date with CRC screening (n = 44). Study-defined relative age ranges were used to identify studies reporting barriers for younger age (50-64) groups. Bibliometric analysis explored pairwise frequencies of barriers, and these relationships were visualized as a network to illustrate the frequency and co-occurrence of younger age and CRC screening barriers. Results: In studies reporting adherence to any test by age (n = 9), adherence was 38-48% for younger and 51-61% for older age groups. Of the 44 studies, 24 quantitative studies identified younger age as a barrier and 3 qualitative studies explored age-specific barriers. Bibliometric analysis (n = 27) showed that patient-level barriers (e.g., ethnicity, no or public insurance, limited CRC knowledge, and embarrassment) were common and frequently co-occurred with younger age as a barrier. The most common provider-level barrier co-occurring with younger age was lack of provider recommendation. Conclusion: Patient- and provider-level barriers to CRC screening are frequently co-reported in studies reporting younger age as a barrier. Studies are needed to confirm whether these barriers also exist in 45-49 year olds. Optimizing screening adherence for younger age groups not up-to-date on CRC screening will likely require interventions and strategies to address these barriers.Figure 1.: Frequency and Co-occurrence of Patient- and Provider-level Barriers with Younger Age Caption: This network (n = 27 studies) visualizes frequencies of each barrier and pairwise frequencies for each barrier when younger age is also a barrier (co-occurrence). Barriers were included in the network if they occurred at least twice. Patient-level barriers are shown in orange, while provider-level barriers are shown in blue. Circle (node) size indicates frequency of a given barrier, and the spatial proximity between two nodes is determined by the pairwise frequencies of the two barriers, illustrating how often the two barriers are reported in the same study. Commonly co-occurring barriers are pulled closer together in the visualization by the strength of pairwise frequencies and shown as links between the nodes. For example, barriers such as ethnicity, insurance, limited CRC knowledge, and fear are common patient-level barriers; and lack of a provider recommendation is a common provider-level barrier. Moreover, the proximity of younger age and income barriers, for example, indicates that these barriers are frequently reported together.