Consistent with other research,5–7,11,16,19,21,24–28,37–38
this study found that patients' most important global reasons for not undergoing CRC screening were the failure of clinicians to suggest testing and patients' lack of knowledge that testing is necessary. Similarly, lack of a physician recommendation was among the top five barriers for all modalities except colonoscopy.
Interestingly, in formative research to develop the questionnaire (the open-ended question about CRC screening and the focus groups) in a similar population, the failure of a physician to recommend the test was infrequently cited as a barrier (only five of 317 open-ended responses listed this as a barrier).14
However, the questions had different reference points; the formative work asked respondents about “the most important
reason people do not have these screening tests” whereas the comprehensive barrier instrument asked respondents what “would make it difficult for you
…” Individuals may be cued by the framing (“people” versus “you”) and/or response options (open-ended or fixed) to consider external explanations for their own behavior but otherwise cite personal opinions and factors within their control as barriers to screening.
A key finding of this study is that barriers to screening are not homogenous across tests and that test-specific barriers warrant consideration in designing strategies to promote screening. For example, concerns about bowel preparation/laxatives, discomfort, and having a tube inserted in the rectum were the leading barriers to undergoing endoscopy, and distaste for handing stool and stool cards were among the top five barriers to FOBT.
The finding that barriers are perceived differently by patients who have never been screened for CRC and those who have had CRC tests calls attention to the need to address prior experience with screening in messages and interventions. A “dose effect” in barrier scores was observed: highest among never-screened respondents, intermediate among ever-screened respondents who were overdue for retesting, and lowest among people adherent with guidelines. Whether low barriers are the cause or consequence of prior exposure to CRC screening cannot be determined from these data, which are cross-sectional in nature. The rank order of barriers also differed by adherence status, suggesting that strategies for maintaining adherence to screening should emphasize different priorities than those for promoting testing among patients who are overdue and for convincing individuals to undergo their first test. For example, the notion of having a tube inserted in the rectum (for flexible sigmoidoscopy, colonoscopy, or barium enema) was a leading barrier among those who were never screened and less a barrier among those who had undergone the tests, suggesting a greater need to mitigate anxiety on this point to reach the never-screened population. While the rank order varied, the mean item scores for any barrier did not exceed 3.0 on the 5-point scale, suggesting that people did not overwhelmingly invoke any single listed barrier. Thus, attention to the relative importance of multiple barriers is perhaps even more meaningful. Intervention strategies to increase CRC screening should not solely address one screening barrier but should deal holistically with the tableau of barriers that patients confront.
These findings raise a question about whether colonoscopy is being recommended perhaps to the exclusion of other test options. The failure of clinicians to recommend testing and not knowing that testing was necessary were cited among the top five barriers for FOBT, flexible sigmoidoscopy, and barium enema, but not for colonoscopy, suggesting that physicians may present colonoscopy as the only screening option. This finding is consistent with national data showing that colonoscopy rates are increasing while FOBT and sigmoidoscopy rates are decreasing.5,39,40
While the success of the medical and public health community in increasing colonoscopy screening may be beneficial, it may ultimately restrict the number of patients who are screened for CRC if alternative options are not offered to patients with other preferences.41
Unlike colonoscopy, FOBT is the only screening test that has been demonstrated to reduce CRC mortality in randomized trials,42–45
but it is often viewed as inferior by both physicians and patients. Modeling studies suggest that a program of high-sensitivity FOBT screening rivals the capacity of colonoscopy screening to reduce mortality and has lower risks;46,47
all major national guidelines promote FOBT as a recommended option.3,4
Consistent with other studies, these findings underscore the importance of access barriers such as cost, limited health insurance coverage, and high insurance deductibles. The survey was administered in 2007, which was followed by a major recession, increased cost-shifting of insurance premiums and copayments to patients, higher unemployment rates, and a larger number of uninsured families. Inadequate access to care and financial challenges may now pose a more prominent barrier to CRC screening than when this study was conducted.
Finally, results indicate that misconceptions continue to prevail as barriers to CRC screening, indicating a continued need to educate patients that screening is necessary in the absence of symptoms or a family history of CRC.
These findings should be considered in the context of several possible limitations. First, their generalizability may be limited. Respondents were patients from 12 family medicine practices in Virginia who returned a mailed questionnaire and a large proportion were adherent with CRC screening guidelines. This patient sample may not fully represent the perspectives of the general population, particularly those who lack access to healthcare, a major barrier to CRC screening, or those who are non-adherent to screening guidelines. However, although the rank order differed, the same top five barriers were reported by all three subgroups in this study, regardless of adherence status. Additionally, these barrier estimates, in a relatively well-screened population, are potentially different compared to barriers in a nonpatient, general population. Second, all possible barriers may not have identified; barriers that were infrequently mentioned during questionnaire development were excluded due to concern about respondent burden. Third, despite extensive cognitive testing of the instrument, responses may have been influenced by the specific wording or sequence of the questions and uncertainty about response options. The relative importance of barriers based on the analysis of mean scores may differ from the ranking respondents might assign if asked to rank order the barriers themselves. Fourth, significant differences in barrier scores may have limited clinical significance.
To our knowledge, this is the most extensive examination of the barriers to CRC screening reported by patients. Heterogeneity in barriers to CRC screening carries obvious practice and policy implications. The approach taken by clinicians in counseling patients about CRC screening and by public health programs in encouraging CRC screening should consider the barrier profile of the patient or target population. Interventions to increase screening must take special note of the modalities being promoted and the composition of the target population with respect to screening status, and their effectiveness should be tested in prospective studies. The data suggest the need for initiatives to increase the promotion of CRC screening by physicians and, in particular, to make patients aware of the options available for testing in addition to colonoscopy.