Colorectal cancer (CRC) screening represents a challenge for many primary care practice settings. Nationally, 53% of age-eligible individuals have been screened in a manner consistent with guidelines1
. Improving on these rates is complicated by the fact that current guidelines equally endorse multiple screening modes2–4
. Depending on the guideline, the list of endorsed options includes anywhere from three to six of the following: fecal occult blood tests (FOBT) annually; fecal DNA every 3 years; sigmoidoscopy, computed tomographic (CT) colonography, or double contrast barium enema every 5 years; sigmoidoscopy every 5 years with high sensitivity FOBT every 3 years; or colonoscopy every 10 years2–4
. Given the lack of empirical evidence to support the superiority of any one mode over others, the US Preventive Services Task Force (USPSTF) and others have explicitly recommended involving patients in the choice of which CRC screening mode to use2,4
, and at least one large, integrated health-care system has formalized this recommendation into policy5
. However, recent observational studies suggest that the majority of patients are not asked about their preferences6–8
or offered a choice of CRC screening mode8
, that the majority of providers recommend only one or two CRC screening options to their patients9
, and that when a choice is offered, it tends to be limited to FOBT and colonoscopy9
. Would more systematically offering a choice of all endorsed CRC screening modes be beneficial? The answer to this question has been the subject of some debate in the CRC screening literature.
Many (including the USPSTF) have argued that providing patients with a choice of mode will increase CRC screening adherence4,10–12
. This perspective has been challenged by concerns that “information overload” resulting from too many options might lead some patients to opt out of screening altogether13,14
. Below we critically evaluate the relative merit of these opposing views, and make an assertion that future decisions about the number of CRC screening modes to offer in practice would more productively be focused on organizational level considerations thus far neglected in the debate on this issue.
Some theoretical support for the assertion that a choice of CRC screening modes will increase adherence can be derived from Self-Determination Theory15,16
, which asserts autonomy is an important determinant of intrinsic motivation. Providing options will, in theory, increase feelings of autonomy and sense of control over one’s outcomes, both of which have been shown to enhance intrinsic motivation to perform or act on any choices made16
Additional support for a positive association between choice and adherence can be derived from classic utility theory17,18
, which asserts that people are motivated to act on things that maximize their unique preferences, or “utilities.” Extending this assumption to health behavior, if there is variation in preferences regarding the most desirable attributes of a product or service across individuals and these attributes can be varied across products or services, then offering a wide variety of products or services (representing a range of potentially desirable attributes) will be preferable because it will increase the likelihood that each individual will find and act on an option that satisfies his or her unique preferences. Studies comparing preferences for four or more recommended CRC screening options do suggest there is variation in mode preferences and the value patients assign to attributes related to preferences11,19–25
. However, evidence that the vast majority of patients prefer either FOBT or colonoscopy20–23,25
calls into question the value of investing in the more rarely preferred screening modalities, particularly in settings where high adherence rates have already been achieved using a screening approach emphasizing a single mode26–28
An argument for a negative association between choice and adherence can be derived from Self-Regulation theory, which posits that making a choice is a self-regulatory process that requires cognitive effort. Choices that are particularly complex (due for example to a large volume of options) can lead to cognitive overload, which can exhaust finite cognitive resources that might otherwise be directed toward motivation, and thereby dampen enthusiasm to make a selection29–31
. Decision scientists would argue that decision support interventions (such as decision aids) that break complex decisions into discrete, manageable steps will reduce cognitive overload, thereby reducing any negative effects of numerous options on motivation and adherence.
In the general literature, there is strong evidence for a benefit of some choice
(versus none) on outcomes. A meta-analysis of 41 studies examined the effect of choice on motivation and found a statistically significant positive association between some choice and intrinsic motivation16
. In the CRC screening literature the evidence to support the benefits of choice is less decisive. Three randomized trials have compared adherence rates across experimental groups offered some versus no choice of mode (Table , rows 1–3). In the first two studies there were no significant differences across experimental groups32,33
. In the third trial, the colonoscopy only group had significantly lower screening rates than the FOBT or colonoscopy choice group, but the FOBT only group did not34
. One randomized trial compared experimental groups receiving a five-option, computer-based decision aid to a usual care control group and found significantly higher screening intention scores in both intervention groups (Table , row 4)35
. However, it is not clear whether the intervention effect was due to choice or the information on CRC and the benefits of screening provided in the decision aid.
Randomized Controlled Trials Evaluating the Effect of Unsupported Choice on CRC Screening Motivation and/or Adherence
Two randomized trials from the CRC screening specific literature comparing groups offered a choice of 5–6 screening modes with and without decision support provide an opportunity to examine whether the effect of choice on adherence is more favorable when decision support is offered (Table , rows 4–5). The findings from these two studies are equivocal. The first study, which used an interview-based decision tool for intervention subjects and examined adherence using medical records 2–3 months post intervention found no significant difference in adherence across groups36
. The second study, which used a web-based tool and examined adherence 6 months post intervention using self-reported data, found higher adherence in the decision support group37
Finally, there is no evidence in the limited available literature to support an effect (either positive or negative) of the number of options
on motivation or behavior. The meta-analysis mentioned above found no significant association between the number of options (categorized as 2, 3–5, or 5+) and motivation16
, and we found only one CRC screening study that evaluated the effect of the number of options presented. This pilot study of 62 patients compared screening intentions of those randomized to a two-option versus a five-option computer-based decision aid and found no significant differences in intention scores across groups38
. Furthermore, the very small differences in intention scores are unlikely to result in meaningful differences in adherence. Although one additional randomized trial evaluated the effect of a three-option CRC screening decision aid on adherence, this study does not adequately assess the effects of choice because the intervention included a provider prompt39
Given the above evidence, we argue that an association between choice and CRC screening adherence cannot be a decisive argument for or against offering a choice of screening options in practice. Other considerations will therefore need to be taken into account in selecting a CRC screening strategy.
We posit that the most likely reason that a choice of CRC screening mode is not more frequently offered in practice is that there remain significant organizational level barriers to doing so, including resource constraints associated with providing all screening modes (particularly colonoscopy)14,40–42
and concerns about the additional burden that adequately educating patients about multiple modes might place on providers43
. Although web-based and other self-administered CRC screening decision aids offer the potential to support patient choice while minimizing the burden placed on primary care providers37
, integrating these approaches into routine care will still require a significant practice change in most settings. Lessons learned from the Robert Wood Johnson Foundation Pursuing Perfection initiative44
suggest that organizational impetus is an important factor in determining successful practice change. Achieving this impetus for change in settings (including most European countries, and at least to large integrated health-care systems in the United States)26,27,45
that currently emphasize a single or reduced set of screening strategies will require a compelling argument for what benefits will accrue to the organization or population by making the change. Will it increase adherence, reduce costs, attract young healthy patients, enhance patient or provider satisfaction, or produce some other valued benefit? We have already established that offering a choice is unlikely to affect adherence, and as we articulate further below, adherence is just once piece of the larger puzzle that makes up a successful screening program. The screening-eligible population primarily consists of an older, higher risk demographic that would likely not to be attractive to health insurers. If offering a choice of screening mode would require additional time investments from primary care providers, it is unlikely to increase job satisfaction. Because any change in practice will require additional time, resources, and leadership from the health care organization, it is unlikely that offering a choice of CRC screening modes would be cost saving. Finally, given that the vast majority of patients prefer either FOBT or colonoscopy, expanding the options offered beyond these two is unlikely to improve satisfaction. Therefore, where the impetus for change will come from to support a switch from a single or reduced modality screening program to one that offers all endorsed modes is not readily apparent.
From our perspective, one of the most compelling rationales for the optimal number of CRC screening modes is a consideration that has not yet been raised in recent debates about the ideal CRC screening program. The dialogue thus far has focused primarily on the first steps of the screening process—the decision to be screened and the selection of a modality. However, the most effective screening programs are those designed with an appreciation of the fact that screening is a process that begins but does not end with the choice of mode or even the completion of a screening test. To be effective at reducing mortality, positive CRC screening results must be followed by diagnostic evaluation and, if necessary, effective treatment and/or surveillance; and negative CRC screening tests need to be repeated over time. Recent evidence suggests that many individuals screened positive for CRC fail to receive appropriate and timely diagnostic evaluation46–58
, and treatment52,53,60
, and that repeat screening rates are far from optimal61
. Closing these gaps is essential to reducing CRC mortality rates and as much a part of building an effective CRC screening program as facilitating screening selection and completion. Several studies point to the importance of timely notification procedures58
; tracking systems58,63
; and documented agreements across services involved in CRC screening, diagnosis, surveillance, and treatment to facilitate care coordination and communication for addressing these gaps63
. The challenges of successfully executing these elements increase as the number of services involved increases. Arguably, an organization should only offer those CRC screening modes for which they have standardized systems and capacity in place to assure that: (1) effective communication and coordination of care across these various services is achieved, and (2) any warranted diagnostic evaluation, surveillance (including repeat screening), or treatment is completed.