Background Singapore has a national CRC screening programme for residents aged ≥50 years, as screening reduces CRC-related mortality and morbidity. Screening uptake is known to differ among various ethnic groups both locally and internationally. This cross-sectional study sought to explore ethnic differences in factors associated with CRC screening among nonadherent patients.

Methods 529 patients were recruited from a public polyclinic, of which 349 (66.0%) were nonadherent to screening (i.e., no FOBT within the previous year or colonoscopy within the last 10 years). Patients completed a questionnaire measuring sociodemographic data, behavioural factors based on the health belief model (HBM), screening intention, and sources of screening information.

Results Significantly more Malays were nonadherent (73.3% of 146) compared to Chinese (60.7% of 252) and Indian (68.0% of 131). Nonadherent Malays were less likely to hear about screening from friends/family (36.6%; p<0.05), while nonadherent Chinese were less likely to hear about screening from polyclinics (38.0%; p<0.05). Perceived susceptibility and cues to action predicted screening intention only in nonadherent Chinese (pseudo R²=0.19, p<0.01). HBM factors did not significantly predict screening intention in nonadherent Malays and Indians.

Conclusions A high proportion of primary care patients are nonadherent to CRC screening guidelines, but key gaps in information sources remain among ethnic groups. Religious and cultural nuances may be more crucial in influencing individuals’ intentions to screen.