CRC screening had been proven to reduce morbidity and mortality from the disease, but only 26.7% of our surveyed population had a current CRC test. This rate is low compared to currency with screening rates reported in the United States , but comparable to a population-based study in Ontario, Canada . Like our study, the Canadian study was conducted in a relatively urban community with access to publicly funded healthcare and in a population with a similarly high incidence of CRC . However, our screening rates are unacceptably low, when 73.3% of the eligible subjects had not gone for screening, despite the fact that nearly 90% were aware that screening helps detect CRC at an early stage which could be cured. There was clearly a discordance between knowledge and action, which we sought to explain using the HBM.
In our study, we found important differences in the HBM domains between men and women that would support a gender specific approach to promoting CRC screening. Firstly, women had more concerns about the risks that might arise from an endoscopic examination, mirroring similar concerns from their Western female counterparts . In addition, they also had greater fears about receiving a positive diagnosis of CRC. This suggests a need for a personalized approach for females, where these intimate issues can be discussed on a one-to-one basis, and reassurance and support offered accordingly. Second, substantially more women cited having family or friends who encouraged them to go for screening, but this surprisingly did not have a significant effect on improving actual screening behavior. This suggests tapping on the network of family and friends will be potentially a useful method in getting across awareness of CRC screening, but unto itself may still be inadequate in actually changing screening behavior.
It was interesting to note that Malay females were significantly less likely to have gone for screening as compared to their Chinese, Indian and European/Eurasian counterparts. This difference persisted despite controlling for economic and educational factors, and the similarity in healthcare access ethnic groups. This ethnic difference in screening behavior was not seen in men, and we would posit there were gender-specific socio-cultural factors that could have influenced Malay women to lag behind in CRC screening. Further studies are needed to elucidate these factors.
The finding that only a small proportion of patients have been encouraged by their doctors to undergo screening was worrying. This was in contrast to a study amongst Medicare consumers in the United States, where 72% had received a doctor’s recommendation to consider CRC screening . More should be done to address this issue because our study found that a doctor’s recommendation for screening was a strong predictor of positive screening behavior in both men and women (adjusted OR 3.50 and 2.35 respectively). This mirrored findings from a recent British study, suggesting that 84% of respondents not only wanted information on the risks and benefits of screening, but also sought recommendation from an “authoritative” source . At the time of the survey, there was no national drive to promote CRC screening. An education program and revised set of screening guidelines directed at doctors have just been launched. It will be beneficial to repeat the survey in a few years’ time, and review what effect these interventions have had practically on the doctors’ behavior and on screening uptake.
Our finding on the positive association of attendance at public talks with CRC screening among women suggests that public education and the media have been effective channels in raising awareness about CRC. The low level of self-perceived susceptibility (39.2% in men and 32.5% in women) is a concern. This was not dissimilar to rates in a large pan-European study, where only 31% of the respondents believed they were at risk of contracting CRC . Outreach to the public through educational programs, advertisements and the mass media are a cost-effective way of increasing awareness of CRC and its rapidly rising incidence in the Asian population. A more impactful method may be through personal encounters. Among women, having a family member with CRC was a strong positive predictor of screening behavior, and one postulate was that seeing or hearing about a relative contacting a malignancy was a reminder of one’s susceptibility and a cue for screening. Among men no such association was found, which would suggest that such a targeted approach pivoted on a family member with the disease would be less impactful than in women.
Our study had some limitations. We did not distinguish between subjects who might have gone for CRC testing for diagnostic purposes rather that for screening. However, we attempted to reduce this bias by excluding respondents who had significant colonic pathology from the analysis on the factors associated with screening. We recognized this was a cross-sectional study, and hence could not exclude temporal bias in the causal effect relationship of psychosocial beliefs and attitudes on CRC screening. For example, the perception of pain could have occurred after CRC screening rather than perceived pain preceding screening. Another limitation was that our study was based on self-reporting, hence some respondents might over-report socially desirable attitudes. We attempted to reduce this bias by training our interviewers to ask questions in an objective and reassuring manner.
However, our study has several strengths. This is the first large scale study describing gender differences in the various behavioral components of the HBM, in an Asian country with a high CRC incidence. There had been a study describing barriers to CRC screening using the HBM, but gender differences were not reported . In addition, our survey was conducted on a moderately large nationally representative sample of a CRC screening eligible population. Moreover, the survey has yielded a high response rate. This study is also one of the few to describe a more clinically relevant “currency with screening” index rather than a simple “uptake of screening” rate.