“If I’m better than average, then I’m ok?”: Comparative information influences beliefs about risk and benefits

https://doi.org/10.1016/j.pec.2007.08.008Get rights and content

Abstract

Objective

To test whether providing comparative risk information changes risk perceptions.

Methods

Two hundred and forty-nine female visitors to a hospital cafeteria were randomized to one of two conditions which differed in whether their hypothetical breast cancer risks was lower or higher than the average women's. Participants read a scenario describing a breast cancer prevention pill and indicated their: (1) likelihood of taking the pill and (2) perception of whether the pill provides breast cancer risk reduction.

Results

Women told that their hypothetical risk of breast cancer was above average were more likely to endorse taking the pill (2.79 vs. 2.23, F = 4.95, p = 0.002) and more likely to believe that the pill provided a significant risk reduction in breast cancer (3.15 vs. 2.73, F = 4.32, p = 0.005), even though the risks were equivalent.

Conclusions

Providing people with comparative risk information changes their risk perceptions. People who have above average risk may feel compelled to take a treatment because they are at above average risk and therefore may not thoroughly consider the trade-offs in the risks and benefits of treatment.

Practice implications

Physicians and decision aid developers must reconsider the practice of communicating “average risk” information to patients.

Introduction

When patients are confronted with difficult medical decisions, health care providers and decision aids both play a critical role in informing patients about the risks and benefits of treatment. This is particularly crucial when the treatment decision confronting the patient is a preference sensitive decision [1], [2]. In these types of decisions, there is not a medically dominant treatment, and the “best” treatment depends on the patient's perceptions of the risks and benefits of treatment. During consultation with patients about these decisions, physicians must consider whether or not to provide their patients with comparative risk information. That is, should they tell a patient the average person's risk of the same health condition (or risks and benefits of treatment)? Will this information help the patient's decision making? This same issue comes to the forefront when decision aid developers are designing decision aids to help communicate the risks and benefits of treatment to patients. Does providing comparative risk information within a decision aid improve patients’ decision-making process?

To put the above in context, imagine a woman with a 6% risk of developing breast cancer in the next 5 years. To reduce this risk, she may consider taking tamoxifen as prophylaxis against a first breast cancer. Randomized controlled trials (RCTs) have shown that tamoxifen can cut the risk of breast cancer in half for women whose 5-year risks exceed 1.66% [3], [4], [5], [6]. However, tamoxifen has broad ranging effects, some beneficial (e.g., reducing osteoporotic bone fractures), and others harmful (e.g., increasing risks of cataracts and endometrial cancer) [7]. Given these advantages and disadvantages, this woman faces a difficult decision regarding whether or not to take tamoxifen. She must decide if a reduction in the 5-year risk of breast cancer (from 6% to 3%) is beneficial enough to make up for the harms of tamoxifen.

Now imagine that this same woman is also told that the average woman faces a 12% risk of developing breast cancer in the next 5 years. Should this comparative risk information change her evaluation of tamoxifen? Standard models of rational choice hold that patients’ decisions about whether or not to undergo interventions should be based on consideration of each person's likelihood of experiencing the associated risks and benefits. Under this rationale, comparative risk information should not change a woman's decision, because it does not change the trade-offs. Her 5-year risk of breast cancer is still 6%, and the costs and benefits of tamoxifen are unchanged.

Nevertheless, this new comparative risk information could change how she feels about her breast cancer risk and tamoxifen. For instance, the comparative information may influence her perceptions of what it means to have a 6% risk, causing the risk to feel lower than it otherwise would have felt. Likewise, consider an alternative scenario in which this woman was told that the average woman's risk of breast cancer is only 3%. In that case, she may feel particularly alarmed about her own risk. In other words, the risk of breast cancer, and the risks and benefits of tamoxifen, might feel different if people are told that their risk of breast cancer is above or below average, even if their own risk remains unchanged. In fact, some studies have found that comparative risk information has a significant impact on cognitive and affective responses [8]. However, other studies have found that statistics that reflect a person's absolute risk are more powerful than comparative risk information [9].

In this study, we tested whether comparative risk information would influence women's perceptions and decisions about a hypothetical medication that reduces the risk of breast cancer. Participants were told that their (hypothetical) breast cancer risk was below or above average. Using this randomized design, we tested the impact of comparative risk information on perceptions of the medication and of breast cancer risk in general.

Section snippets

Participants

Participants were adult female visitors to a hospital cafeteria approached by research assistants.

Scenario

Participants read a scenario describing an unnamed pill that could reduce a woman's risk of breast cancer by half but was also accompanied by side effects (scenario is presented in Table 1). In both versions of the questionnaire, participant's risk was constant (6%). However, we randomized participants to receive different information about the average woman's hypothetical risk of breast cancer.

Sample

In total, 249 women completed the questionnaire. Their average age was 44.7 (S.D. = 15.1, range 19–86); 5.6% identified themselves as African American, and 89.2% indicated they were Caucasian. The sample was well educated, with 41.5% having obtained a bachelor's degree or higher. Sixty-three percent reported having a close friend or family member who had been diagnosed with breast cancer. Additionally, 48.0% of respondents were employed or training in a medical profession. Health professionals

Discussion

Many health care providers provide their patients with comparative risk information without realizing the impact such information has on patients’ risk perceptions, and perhaps, their decision making. The results of this study show that comparative risk information changes the way women perceive risk. For instance, when women perceived themselves to be at an above average risk for developing breast cancer, they reported that they were more willing to take a drug aimed at preventing breast

Acknowledgments

Portions of this work were presented at the annual meeting of the Society for Medical Decision Making in October 2004. This work was supported by R01 CA87595 and P50 CA101451. Dr. Fagerlin is supported by an MREP early career award from the U.S. Department of Veterans Affairs and Dr. Zikmund-Fisher was supported by an HSR&D Post-Doctoral Fellowship from the Department of Veterans Affairs. Dr. Fagerlin had full access to all of the data in the study and takes responsibility for the integrity of

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The funding agencies had no role in the design and conduct of the study, nor the interpretation of data, or the preparation review, or approval of the manuscript.

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