Mike: Hello, I'm Mike Clarke, podcast editor for the Cochrane Library. Adding to the Cochrane Reviews of screening for breast cancer, a new review was published in May 2024 looking at the research into shared-decision making for this screening. In this podcast, Dr. Marleen Kunneman from Leiden University Medical Center in the Netherlands and Mayo Clinic in the US talks with lead author Dr. Paula Riganti from Hospital Italiano de Buenos Aires in Argentina about the review and its findings.

Marleen: Hi Paula. First of all, thank you for joining today. I wanted to thank you and your co-authors on this very important new review and I am excited for this opportunity to discuss this project with you.

Paula: Hi Marleen, thank you so much, I am delighted to be here.

Marleen: So today we will be talking about shared-decision making. This is  when patients and clinicians collaborate in making decisions about health or care. In shared decision making, these decisions are made based on both the best available evidence and on what matters to the patient. So in the case of your review, women may choose to screen for breast cancer, or they may choose to not screen for breast cancer. Shared decision making is a method of care, it’s not a method to persuade people to make a particular decision. So, having these conversations can be challenging, I imagine. In your experience, how is this in breast cancer screening?

Paula: In many countries, women above a certain age are given the option to do a mammogram, which has been shown to detect early-stage breast cancer, which can save lives and reduce health issues during treatment. However, mammograms can also lead to wrong results, so called false positives, or to unnecessary diagnosis and treatment of a cancer that would have never caused harm or symptoms if left undetected. This means that shared decision-making needs to balance the pros and cons of the mammogram, and to understand the patient’s context, values and preferences.

Marleen: Yes and I realize that this balancing takes place in that patient-clinician conversation, and that it can, but it doesn’t necessarily have to be supported by tools. Previous reviews about breast cancer screening have focused on using decision support tools. How does your Cochrane review differ from these previous reviews?

Paula: Yes, exactly. So, decision support tools, such as leaflets or online guides, can help with shared-decision making but they are neither necessary nor sufficient for shared decision making as you mentioned. There are guidelines that follow the International Patient Decision Aid Standards or IPDAS criteria to guide the development of the decision aids or support tools. In this review we focused on any approach to SDM with or without decision support tools that may or may not adhere to the IPDAS criteria.  So, sometimes, decision support tools only focus on providing evidence-based information without exploring patient preferences and how the evidence fits the patient’s context, which is an essential component of shared-decision making.  It’s also possible for a health care professional to have the conversation with a patient without using decision aids or any decision support tools. Taking all this into account, we wanted to understand more about the effect of shared-decision making on the outcomes that matter most to patients, taking us beyond the earlier reviews on decision aids.

Marleen: Yes, I understand. So, tell me more, what did you want to know specifically about shared-decision making and breast cancer screening?

Paula: Like previous reviews, we wanted to investigate if shared decision making could help women feel more satisfied, confident, and knowledgeable about breast cancer screening choices; but we also wanted to know how well women followed their choice, how involved they were, if they felt anxious or worried and how well the doctors talked to them.

Marleen: Looking at your review, I see that you included a total of 19 trials with nearly 65,000 women. What are your conclusions about the effects of shared-decision making in breast cancer screening?

Paula: We first wanted to look at knowledge, confidence in the decision made and satisfaction. Satisfaction wasn’t measured in any of the studies. In our results we made a distinction between studies that focused only on providing information, studies that focused also on clarifying  values and preferences, and studies that did all of this but having real life conversations and evaluated real life conversations. So, studies focused only on providing information about the pros and cons showed this might help women know more, but we're unsure if they help them be certain about their choice or reduce their worries. The studies that focused on clarification of values and preferences can help people feel better about their choices, know more, and help them decide and feel more certain, but it has little to no impact on anxiety or cancer worry. The only two studies that focused on evaluating real life conversations, with two or more people having a discussion about pros and cons and clarification of values and preferences, found little to no impact on knowledge, but didn’t measure any of the other outcomes we were interested in for the review. We also didn’t find any studies that measured if women liked the process or followed their choice, their level of involvement, or how well the doctors talked to them.

Marleen: Ok, so there’s a lack of evidence for some of these issues of interest and there are some uncertainties in the evidence that you did find, what’s your take-home message after doing this review?

Paula: Firstly it’s relevant to mention how research into shared-decision making has evolved in the last two decades. All but one of the studies in our review were done between 2005 and 2023, with earlier studies focused only on providing balanced information, while more recent studies incorporated the clarification of values and preferences. Knowledge was the most commonly reported outcome, but different scales were used to measure it, making it difficult to compare results and have robust evidence. And, as I mentioned, there was little to no difference in anxiety and cancer worry, but the tools used to measure these outcomes had been designed for studies on communicating a cancer diagnosis, but not for screening decisions. Interestingly, studies only measured if women followed the evidence-based recommendation, but not if they chose an option that aligned with their values and preferences.

Marleen: So, moving forward, what do you think the research community should consider when conducting new studies in this area and how can we learn more about this review and find it?

Paula: We need more research into the effects of shared-decision making beyond the use of decision support tools or strategies that just provide balanced information. This might need a core set of outcomes and the inclusion of more outcomes that are relevant to patients. And, to finish, the review is available online at Cochrane Library dot com, with a search for ‘shared-decision making and breast cancer screening’.

Marleen: Thank you very much Paula, for sharing your findings and views!

Paula: Thank you Marleen.