Our study demonstrated the challenges of achieving informed decision-making for cancer screening decisions. Even though all participants reported discussing screening and most described themselves as being informed about screening tests, half or less of the participants in each module were able to correctly answer even one knowledge question. Respondents rated providers as their most important information source, and reported that providers most often initiated screening discussions and generally recommended screening. However, participants reported that providers did not routinely elicit screening preferences and screening discussions were much more likely to address the pros of screening compared to the cons of screening.
The consistently poor performance on knowledge questions about cancer incidence and mortality across all cancer types was disconcerting. Knowledge of the clinical issue is considered an essential element for informed decision-making (3
). Although most participants considered themselves informed about screening, the proportions that correctly answered both incidence and mortality questions ranged from only 2.9% (breast cancer) to 20.7% (colorectal cancer, men) among those who considered themselves extremely well informed (= 10). Although most respondents considered themselves to be at average or low risk for cancer, they consistently and markedly overestimated the risks for cancer incidence and mortality across all levels of perceived risk. They also overestimated the predictive value of PSA tests and mammography for detecting cancer. One possible explanation for these findings is that cancer has been widely publicized in the popular media and the messages often do not accurately reflect the burden of disease and the relatively limited benefits of screening (20
). Most messages uncritically support screening, often failing to address absolute risks, potential harms, alternatives, uncertainty, and evidence-based screening guidelines. A consequence of these messages, as shown in a national survey of adults without a history of cancer by Schwartz and colleagues (24
), was that most (87%) adults believed that routine cancer screening is almost always a good thing and 74% believed that finding cancer early saves lives most or all of the time.
Health care providers can play an important role in conveying accurate information about cancer screening to patients. Our participants reported that the process for discussing cancer screening usually began with the provider raising the issue. Participants consistently rated provider information as being far more important than information from other sources such as family and friends or the media. However, the exaggerated perceptions of cancer risk suggest that the media messages are perhaps more powerful than participants acknowledge. Part of the problem may be that providers are not sufficiently countering the media messages by providing patients with comprehensive and objective information about screening.
Even though many experts emphasize that providers should be discussing the benefits and risks of cancer screening (2
), patient surveys and interviews of both patients and providers agree that patients often do not receive enough information to support screening decisions (6
). The DECISIONS results confirmed the limitations in cancer screening decisions, but went beyond the existing literature by comprehensively characterizing the decision-making process across multiple screening decisions.
Although most participants felt that screening had been well explained by the provider, they reported that discussions for each of the cancers consistently addressed the pros of screening more than the cons. While the pros of screening were discussed “a lot” most frequently for breast cancer, nearly all discussions addressed the pros to some degree. However, the subjects reported that 70% to 80% of discussions failed to address the cons of screening at all. This may reflect a biased recall of the discussions, particularly given the general enthusiasm for cancer screening (24
), with respondents less likely to retain negative information. Nonetheless, in describing the screening discussions, participants also reported that health care providers frequently had opinions about screening, with the majority favoring screening so that a biased presentation is certainly plausible. Provider recommendations are recognized as powerful factors for undergoing screening (29
), but when presented without discussing the pros and cons they undermine the goal of achieving informed decision-making (3
The majority of participants reported being satisfied with their level of involvement in the decision. Indeed, studies have shown that patients value being involved in the decision-making process for cancer screening (4
). However, most discussions reported by our participants did not clearly meet criteria for being informed because providers did not routinely elicit screening preferences, particularly for colorectal cancer. Braddock et al have shown that patients are often not made aware of their opportunity to participate in decision making, emphasizing that this process should include patients exploring their preferences (3
A striking finding in our survey was the relatively low reported uptake of colorectal cancer screening after a discussion. Only about 70% of women and 79% of men who reported having a discussion underwent colorectal cancer screening compared to 86% for prostate cancer screening and 90% for breast cancer screening. A previous analysis of men aged 40 and older who completed the prostate cancer screening module found that a provider recommendation for screening was the most important discussion factor associated with undergoing testing (12
). In the current analyses, we observed lower uptake for colorectal cancer screening even though most women and men did receive provider recommendations for screening, valued provider information, and felt well informed.
Additionally, only about 63% of participants indicated that they were extremely confident in their colorectal cancer screening decision; this was significantly lower than reported by women completing the breast cancer module (85%), suggesting some ambivalence. Embarrassment and anxiety about the screening tests may be a barrier for even informed patients (33
). Lafata et al identified other issues in a survey of primary care patients where only 61% of those who discussed screening actually underwent testing (7
). Discussing lower endoscopy and instructing patients on how to make appointments and get test results were associated with a greater likelihood of screening. However, patients who were offered a choice among multiple screening test options or who wanted additional information were less likely to be screened. This suggests that incomplete information may hinder informed decision-making.
One possible solution for improving the decision-making process is to offer patients decision aids. These aids are defined as interventions, which can be written, oral, video, or web-based, that are designed to help patients make decisions by providing information on the disease, presenting alternative strategies, describing the possible beneficial and harmful outcomes, and helping patients clarify their values (2
). Given that screening discussions often are incomplete or omitted, using a decision aid would allow providers to be able to consistently present comprehensive, objective information. Decision aids have been shown to increase shared decision-making, improve knowledge, and improve concordance between patients’ values and their decisions (35
). Prostate cancer decision aids have also been associated with decreased interest in screening (36
), while other cancer-specific decision aids have increased uptake of breast (37
) and colorectal cancer screening (38
). Because providers are highly rated as important sources for cancer screening information, having them provide decision aids could be an acceptable and powerful antidote to misleading media messages and receiving incomplete information.
The survey had some important potential limitations. Participants were asked to recall discussions that could have occurred up to 2 years before completing the survey module. This step could have led to recall bias because we did not attempt to validate the responses. However, the screening rates were similar to other national surveys, including the National Health Interview Survey (40
) and Health Information National Trends Survey (30
), where participants were asked about screening or discussions that had occurred within the previous year. Additionally, the participants were highly selected because most had access to health care, and all had telephones and spoke English. We also required that a module participant had either undergone or discussed cancer screening within the past 2 years. Study results may not be generalizable to lower income, minority, or less health-conscious populations. We also were unable to determine whether respondents who reported testing within the past 2 years had ever been previously tested. A screening discussion might be structured differently for patients with previous testing, with less effort to ensure informed decision-making. However, given changing guidelines and new research findings, providers should not assume that screening preferences would necessarily remain constant. While we assessed cancer knowledge in association with informed decision-making, we were not able to determine whether the health care provider actually provided any cancer information. Furthermore, the knowledge questions, though based on validated measures, addressed only a limited spectrum of cancer screening knowledge. We did not ask subjects about the potential downstream consequences of screening, including false positive tests and undergoing biopsy, overdiagnosis, and complications from overtreatment, that are also considered important for making informed decisions for cancer screening. Finally, we are not able to know what kind of information is most important for decision making from a patient’s perspective. However, the poor performance on the knowledge questions suggests that patients may not be able to accurately determine whether they are well informed. Patients should have some key objective knowledge, though determining what constitutes essential knowledge remains a challenge.
Cancer screening discussions across all screening tests apparently did not routinely meet criteria for informed decision-making. Participants reported that health care providers frequently failed to discuss the cons of screening and did not routinely elicit patient preferences. Although participants reported feeling well informed, they performed poorly in answering knowledge questions, and significantly overestimated incidence and mortality risks and the predictive values of PSA tests and mammography. Participants highly valued health care provider information and recommendations, suggesting that providers can have a vital role in ensuring that informed decision-making occurs for cancer screening decisions. Further research should address strategies, such as provider training, decision aids, or coaching interventions, to facilitate this process.