Study on the influencing factors of community residents' willingness to participate in colorectal cancer screening: a cross-sectional survey based on the Shanghai's major public health project

<h2>Abstract</h2><h3>Background</h3> Since 2013, the Shanghai municipal government has been offering free colorectal cancer screening services (FOBT) to community residents aged 50-74. By 2023, 3.044 million people had participated in it while many residents do not especially those under 65 years old. According to follow-up data, less than 30% of individuals who tested positive on the initial screening have undergone diagnostic colonoscopies. This study applies the Health Belief Model to analyze factors influencing residents' participation in initial screening and colonoscopy for colorectal cancer in Shanghai, which will provide evidence for improving the effectiveness of the screening program. <h3>Methods</h3> This study was conducted through stratified random sampling across all 248 community health service centers in Shanghai. A total of 7,936 questionnaires were collected, with 7,601 deemed valid. The interviewed residents completed the Chinese version of The Champion Health Belief Model Scale. The "perceived barriers" items for initial screening and colonoscopy participation willingness were different and reverse-scored separately. The study analyzed the impact of each dimension on residents' willingness to participate in colorectal cancer initial screening or colonoscopy through logistic regression models, and conducted heterogeneity analysis by subgroups. <h3>Findings</h3> For the willingness to participate in initial screening, the total score for 5,635 residents who had participated in initial screening was 120.3±10.4 points, compared to 115.2±11.4 points for the 1,966 residents who had never participated (p<0.05). Controlling for other influencing factors, two protective factors for all respondents' willingness to participate in initial screening were perceived susceptibility (OR=1.09, 95% CI: 1.07-1.11, p<0.001) and self-efficacy (OR=1.31, 95% CI: 1.28-1.35, p<0.001). Three risk factors were perceived benefits (OR=0.98, 95% CI: 0.95-1.00, p<0.05), health motivation (OR=0.93, 95% CI: 0.92-0.95, p<0.001), and perceived barriers (OR=1.09, 95% CI: 1.07-1.11, p<0.001). This was consistent with the subgroup analysis results for residents aged 65 and above. The five dimensions that affected older residents were lower susceptibility to colorectal cancer, lower perceived benefits, stronger non-screening motivation, weaker self-efficacy, and more perceived barriers. Residents who aged under 65 were affected by four factors, excluding perceived severity and perceived benefits. For the willingness of residents with positive initial screening results to undergo colonoscopy, 3,740 respondents provided answers. The colonoscopy group scored 124.0±10.5 points, higher than the colonoscopy refusal group's 120.9±10.8 points (p<0.05). Controlling for other influencing factors, two protective factors for all respondents' willingness to undergo colonoscopy were perceived susceptibility (OR=1.07, 95% CI: 1.05-1.09, p<0.001) and self-efficacy (OR=1.06, 95% CI: 1.02-1.10, p<0.05); One risk factor was perceived barriers (OR=1.07, 95% CI: 1.05-1.09, p<0.001). This was consistent with the subgroup analysis results for residents aged 65 and above. The three factors that affected older residents included insufficient awareness of colorectal cancer susceptibility, weaker self-efficacy and more perceived barriers. For the subgroup aged under 65, only perceived susceptibility and perceived barriers influenced their willingness. <h3>Interpretation</h3> The factors affecting screening willingness varied at different screening stages and among different age groups. The study suggests that to more effectively mobilize residents to participate in initial screening and improve compliance with colonoscopy, targeted publicity strategies and other intervention measures should be designed differently.