Abstract
Introduction: Colorectal cancer (CRC) is easily detectable with screening, but due to a variety of factors, over a third of eligible people do not get screened. One barrier to people getting adequate screening is confusion about what type of test to use. Shared decision making (SDM) is a way for the clinician to help the patient decide about whether to get screened for CRC and if so, which test to use. This scoping review examines literature about shared decision making in CRC screening to identify key factors affecting a patient’s decision.
Methods: We identified studies published from January 1, 2010 through May 18, 2024 through searching 4 databases. Studies were peer reviewed publications in English that investigated the role of shared decision making in colorectal cancer screening in average risk adults, aged 45 –75, in the United States and Canada. Two independent researchers screened all titles and abstracts for eligibility and reviewed all included full text articles. The included studies were examined for themes affecting a patient’s choice of screening test.
Results: Of the 5672 unique records identified, we included 28 studies in this scoping review. Four themes emerged as being important to the process of shared decision making in colon cancer screening: knowledge of specific aspects of each test, clinician recommendation, acknowledgment of strong emotions surrounding screening, and importance of external factors in decisions around screening. Patients relied on family members for information about screening and made decisions about screening using this information as well as logistics of the test chosen.
Conclusion: Future work can focus on the importance of external factors in screening decisions and recognizing and addressing the real emotions about CRC screening.
Introduction
Colorectal cancer (CRC) is the second leading cause of cancer death in the US. In 2023, approximately 153,000 people were diagnosed with CRC and almost 53,000 people died from CRC in the US.1 Although colon cancer is most frequently diagnosed in people over 65, over 10% of new cancers are diagnosed in people under age 50, signaling a 15% increase over the past 20 years. CRC is easily detectable with screening, but due to a variety of factors, over a third of eligible people do not get screened. In 2021, the USPSTF recommended that all adults from 45 to 74 get screened for CRC (“A” recommendation for 50 to 74 and “B” recommendation for 45 to 50).2 Several types of screening tests are available for CRC including stool-based tests, CT colonography direct visualization, and blood tests. Colonoscopy is considered the “gold standard” screening test as it can see cancer but also can find and remove precancerous polyps thereby preventing future cancer. However, doing the bowel preparation for a colonoscopy is difficult for some people and the procedure requires the patient and their support person take a day off work, which may not be financially or logistically possible for everyone.3
One barrier to people getting adequate screening is confusion about what type of test to get and how to decide whether to get screened or not. Shared decision making (SDM), a communication strategy where the clinician explains the potential harms and benefits of any test and the patient discusses what is important to them, is a way for the clinician to help the patient decide about whether to get screened for CRC and if so, which test to use.4,5 The decision making process regarding CRC screening is a complex one that incorporates patient education, socioeconomic, cultural, and psychological components.6 The interaction between a trusted clinician and the patient making the decision can also impact screening decisions.6 A 2020 systematic review looked at decision making about CRC screening within the context of the Health Belief Model and found that perceived susceptibility to being diagnosed with CRC, potential benefits of screening tests, and cues to encourage screening were associated with people getting screened.7 The American Cancer Society (ACS) has developed SDM tools to help clinicians counsel their patients about CRC screening, recognizing that the decision of whether to get screened and further which test to use is potentially confusing but these tools are not widely available.8 Furthermore, the ACS has recommended that clinicians limit choices due to literature showing that having too many choices can be paralyzing for patients.8 The current guidance is unclear for primary care clinicians. Therefore, we sought to determine what factors impact shared decision making related to colorectal cancer screening with the plan of developing guidance for primary care clinicians.
We used a scoping review methodology to evaluate the available data on the use of shared decision making in screening for CRC.9 Our goal in this scoping review was to examine available literature about the decision of whether to get screened and further determine what factors affect a patient’s decision of which particular screening test to use. We looked to the health belief model and grounded theory as theoretical models to guide our analysis as well as a published framework looking at SDM in CRC screening.10 The Health Belief Model is a description of how many people make health-related decisions based on a predetermined set of criteria including their perception of the risk of the disease, the likelihood that they think they will get the disease, and the impact of how screening can affect their risk of getting the disease.7 Using a Grounded Theory approach helped the researchers collect data from each article without a predetermined hypothesis about important factors for SDM. Delineating the barriers and facilitators that affect people’s perceptions and decisions around CRC screening will enable primary care clinicians to focus screening efforts on factors that matter to their patients.
Methods
Our scoping review was conducted in accordance with the JBI methodology for scoping reviews.11 We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines.12 (see Appendix)
Search
The review team collaborated with a research librarian (LC) to develop and execute a comprehensive search of the literature. This search combined controlled vocabulary and keyword terms related to shared decision making in colorectal screening of average risk patients after the development of fecal home test kits (see appendices for full database search strategies). The search was developed in PubMed and then translated into the following databases: Scopus (Elsevier), CINAHL Plus with Full Text (EBSCO), and PsycINFO (EBSCO). All searches were run on May 28, 2024. A date limit of 2010 to present was applied to the search results to exclude records from before home testing was available, as screening methods have changed since then. No other filters (language, publication type, age, etc) were used. Results were downloaded to a citation management software (EndNote) and underwent manual deduplication by the librarian using the method described by Bramer.13 Unique records were uploaded to a screening platform (Covidence) for independent review by project team members using predetermined inclusion/exclusion criteria. (see Appendix for review details)
Screening & Eligibility Criteria
Studies were screened based on the following inclusion/exclusion criteria decided on by the review team: (Table 1). We included peer reviewed publications in the English language and had an outcome of interest centered around shared decision making in CRC screening or the process of decision making for patients when discussing screening options with a health care clinician. Studies were also published in or after 2010 to account for the development of at-home screening tests. Population data from the studies were from average risk adults aged 45 to 75 to account for current screening recommendations. During initial evaluation of abstracts, the team decided to include studies that had broader age ranges as long as the 45 to 75 year age-group was also included. But, studies that focused exclusively on older patients (over age 75) were not included. Finally, we only included publications from the United States or Canada, and only discussed common screening tests used in these countries, such as colonoscopy or stool-based tests. Articles from other English-speaking countries (ie, Australia or the UK) were excluded due to differences in screening guidelines and available tests.
Inclusion and Exclusion Criteria
Two team members (SS and HW) reviewed the titles and abstracts of studies found in the database and determined inclusion or exclusion based on the predetermined criteria. Next, 2 study team members (SS and HW) reviewed full text of publications using the same criteria to examine eligibility for data extraction with a reason for exclusion given if a study was ineligible. Much of this involved reviewing a given study’s methods, their study population, and given results. All screening of studies occurred using the Covidence platform. In each step, 2 independent reviewers (SS and HW) voted on a study’s eligibility. If a conflict arose, a discussion between the 2 initial reviewers occurred or a third independent reviewer (LY) was available as a final vote.
Data Extraction
Data extraction occurred for all eligible studies following the title and abstract and the full-text screens. Articles had their results analyzed independently by 2 members of the study team (SS and HW). Results of interest were centered around shared decision making in colorectal cancer screening and barriers or facilitators to shared decision making (SDM). Examples of study results included preferred test characteristics of patients (ie, home based test, need for preparation, need for medical procedure), emotions regarding testing, and patient preference on the information given by their clinician. These themes were recorded into individual spreadsheets by each reviewer. On completion of full data extraction, the compilation of results was summarized for key themes on how patients make decisions in colorectal cancer screening. The final summarization of themes was performed together as a study team.
Results
Selection of Sources of Evidence
After duplicates were removed, a total of 5672 studies were identified from searches of electronic databases. Based on the inclusion criteria, 5477 studies were excluded, with 195 full text articles to be retrieved and assessed for eligibility. Of these, 167 were excluded for the following reasons: 114 did not discuss the process of decision/making/shared decision making, 16 were outside the US/Canada, 11 were not data-driven articles, 8 were the wrong patient population (either high risk or older than 75, 7 had no data about patients, 5 were not peer reviewed articles, 3 had incomplete studies, 2 had no discussion of colon cancer screening, and 1 discussed a blood test for screening. The remaining 28 studies were considered eligible for this review. (Figure 1—Prisma flow diagram)
We identified 4 main domains that are related to a patient’s decision making about CRC screening. 1. Patients desire detailed descriptions of each test including test accuracy (sensitivity and specificity), the process of the test, description of the procedure, and the likelihood that it will detect cancer to make a decision about whether to get screened and which test to use. 2. Patients place high value on their personal physician’s recommendations regarding CRC screening. 3. There are strong emotions surrounding many of these CRC testing options. Getting a colonoscopy, specifically, triggers deep anxiety for many people. 4. The impact of external factors such as culture, socioeconomic status, and family input have a significant impact on the decision regarding CRC screening. (Table 2) (Figure 2)
Prisma flow diagram.
List of Papers Included in the Scoping Review
Importance of Knowing Test Attributes14–35
Patients want to know details about test attributes to help make their decision. How is the study performed? Can they do the test at home or do they need to go to a health care facility? Most prioritized tests that prevented cancer, were accurate, and sensitive. They also wanted to know the pros/cons of each test, what the preparation for the procedure would entail, details about the actual procedure with logistics (ie, cost, time, transportation). These specific details were important to participants in the studies to help them make a decision about whether to get screened and which test to use. Important details that were discussed included the fact that a colonoscopy is the most invasive test, takes the longest for prep, and necessitates time off work while at the same time is the most effective at diagnosis and prevention of CRC. Home based stool studies, on the other hand, are much easier to perform, but do not have as high sensitivity and specificity for CRC. Most of the participants in these studies rated accuracy and ability to detect and prevent CRC as the most important aspect of their choice.
Examples:
Patients ranked CRC screening tests based on specific criteria in the following order: test effectiveness, features of the test (complications, convenience, procedure, prep) and follow up frequency.25 In this study, ability to detect CRC outweighed convenience and discomfort of the test.
Patients ranked the top 3 attributes of CRC screening tests: sensitivity of the test, risk of a tear, need for a second test26
Risk reduction of a screening test was the most important attribute.14
People designated accuracy as the most important characteristic of a CRC screening test.32
Most important attribute was ability of screening test to reduce the incidence and mortality from CRC and the second most important was to avoid complications.29
Impact of Relationship with the Clinician16,20–24,27,28,30,31,36–38
Patients have high regards for their clinician in these decisions and the recommendation of a trusted clinician had a large impact on their decision. The average person knows nothing about CRC screening so they rely on their clinician to know when it is needed, the purpose of screening, and value their recommendation on some of the tests. SDM is a preferred method of discussion with the clinician, but many people value input from their PCP to help guide them in their decision making and depend on recommendations. They also prefer to learn information about screening from their clinician rather than from a pamphlet or video. The trusting relationship between a PCP and a patient was a significant factor that impacted many people’s decisions about screening for CRC.
Examples:
Clinician recommendations are welcome but patients want a rationale for each recommendation.16
Clinician knowledge, information, lead/initiation, and recommendation were appreciated by patients given their overall positive rating in decision confidence.23
Overall, physician demeanor, attitude, and conversation style matters in SDM as when they approach the conversation in a friendly manner and consider patient perspectives, patients are more likely to report a shared decision being made.37
A trusted physician’s recommendation was important in the decision of whether or not to get CRC screening.31
Acknowledgment of Real Emotions Surrounding Screening16,20,24,27,28,30,31,37–39
The emotions of patients should be considered because of the impact they have on decision making. Patients described fear and stigma influencing their decisions about whether to be screened for CRC and which test to use. Colonoscopy, especially, seems to trigger strong emotional reactions. Many people have fear and embarrassment about the test. Studies described a need for normalization of the available tests and clear and detailed explanations to help people move past their fears. There was mixed data about the effect of providing stories of personal experiences from people who have been screened.
Examples:
Fear and embarrassment about the invasiveness of the colonoscopy is a barrier to screening.27 The process of having a tube inserted into their body is a challenge for many people to overcome.
Discomfort and embarrassment when handling stool is a hurdle for FIT testing.24,30,32 FIT testing is undesirable because patients need to collect their own stool for test completion.
Fear of cancer diagnosis and treatment is a barrier to screening.24 People are afraid of having a positive test result and therefore avoid screening.
Some people want to avoid bad news and had heard about negative experiences from family and friends regarding colonoscopies.16 Many people have heard how hard the colonoscopy prep is and want to avoid it.
Influence of “masculine norms” and stigma of homosexuality related to colonoscopy.39
External Factors That Influence Decision Making24,27,28,34,36,39–41
Patients’ culture, family and socioeconomic status impacted the choice of a CRC screening test. Family support and experiences, ability to communicate with clinicians, and level of education and income affect how people make decisions about CRC screening. Participants are influenced by family members who have received screening and need for transportation and work absences. Family members who have undergone any screening method who share their experience, whether it was positive or negative, can impact patient’s perceptions of the test. Colonoscopy requires transportation to and from the clinic during normal business hours, which can be a strain on patients and their work schedule.
Examples:
A significant positive correlation was found between family support and the incidence of informed decision making about CRC screening.40 Family support allows patients to discuss their values and concerns with a specific test. Additionally, family members who have experienced CRC screening themselves can be another aid in decision making.
Less acculturated individuals (more Spanish speaking at home) were less likely to prefer an active role in CRC decision making.41
Higher education and income is associated with perceived benefits to screening and greater knowledge of CRC/screening.34
Family and community groups who discuss CRC screening and experiences greatly impact decisions about screening.39 Learning about the testing process from those who have pursued it gives patients an expectation of the preparation, process, and recovery of a given test.
Discussion
This scoping review identified 4 key themes that affect a patient’s choice of CRC screening (whether to get screened and if yes, which test to choose) through shared decision making with their primary care clinician. These themes highlight the importance of the primary care clinician’s role in the shared decision making process, as well as the importance of providing the patient with adequate information to make the most effective decision for themselves. Existing literature describe the determination of health belief model constructs (such as perceived benefit of screening and assessment of personal risk of getting CRC) and how they directly relate to a patient’s screening intention or behavior with the goal of increasing screening rates,7 but our article goes one step further with identifying themes related specifically to the act of shared decision making for CRC screening. It focuses less on the outcome and more on the process of shared decision making and what factors are important for patients in that process. This article is innovative in that it offers a foundation for the creation of new algorithms or decision aids for decision making around CRC screening that acknowledge strong emotions related to CRC screening, clearly delineate potential harms and benefits of each screening method, leverage the existing relationship with the PCP, and involve family and friends in the decision making process.
In particular, the focus on addressing emotions surrounding the process of CRC screening is a useful finding. Primary care clinicians can focus on their relationships with patients, making sure that people get adequate information about different CRC screening options, and acknowledging external factors that impact decisions. But, developing tools to address the fear and embarrassment that surround colonoscopy screening specifically must be a priority. Dozens of handouts and articles are available to convince people to not be afraid of a colonoscopy. These articles included facts as well as testimonials. Data in our sample and in the literature is mixed about whether people want to hear personal stories about colonoscopies.20,27,42,43
Limitations for this scoping review include only using studies in the US and Canada as well as studies only in the English language. Given that 1 of the 4 themes identified was external factors that influence decision making, of which culture and language are included, this limitation does impact whether these results can be attributable to other non-North American patient populations, as different sociocultural conditions can play a role in the concept of shared decision making. Studies included were also limited from 2010 onwards, and we only used completed studies with an outcome related to shared decision making in CRC screening. Other publications or gray literature like dissertations or conference abstracts not meeting our criteria were not included, which narrowed our sample size and could potentially lead to publication bias. These limitations had the potential for some relevant articles to be missed from our initial screen. General limitations to scoping reviews is the ability to only include articles that have been published within our parameters.
Future work in the creation of a formal framework for physicians to use when discussing CRC screening with their patients can be considered. In clinic visits where many patient concerns are addressed, having something akin to an algorithm or decision aid outlining options for CRC screening that incorporates these 4 factors that patients can review in advance of their visit could potentially improve screening rates and help patients feel more comfortable in their choice. A study including the creation of such a decision aid and measuring outcomes of number of CRC screening tests ordered, adherence to completing the ordered test, and patient satisfaction with the decision making process could be considered.
Conclusion
Through our scoping review of studies related to shared decision making for CRC screening, 4 main themes were elucidated as factors contributing to a patient’s decision regarding screening: information about the screening test, a patient’s relationship with their primary care clinician, a patient’s emotional reaction to the screening test, and external factors such as culture/family/socioeconomic status. These themes are important for primary care physicians to know as they proceed with shared decision making with their patients in this realm.
This information can be used to create a new framework that primary care physicians can use as a more formalized and efficient tool for shared decision making for CRC screening. Future research should evaluate if addressing the themes identified by this scoping review within a primary care visit contribute to increased rates of CRC screening.
Appendix
Notes
This article was externally peer reviewed.
Funding: Funding for this study was provided by the UWDFMCH Summer Student Research and Clinical Assistantship program which supported HW.
Conflict of interest: The authors have no conflict of interest.
To see this article online, please go to: http://jabfm.org/content/38/4/635.full.
- Received for publication November 24, 2024.
- Revision received March 24, 2025.
- Accepted for publication April 7, 2025.
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