Breast Cancer Screening Information Study

How information about overdetection changes breast cancer screening decisions: a mediation analysis within a randomised controlled trial

2026-04-29T05:44:03Z

How information about overdetection changes breast cancer screening decisions: a mediation analysis within a randomised controlled trial Hersch, Jolyn; McGeechan, Kevin; Barratt, Alexandra; Jansen, Jesse; Irwig, Les; Jacklyn, Gemma; Houssami, Nehmat; Dhillon, Haryana; McCaffery, Kirsten Objectives: In a randomised controlled trial, we found that informing women about overdetection changed their breast screening decisions. We now present a mediation analysis exploring the psychological pathways through which study participants who received the intervention processed information about overdetection and how this influenced their decision-making. We examined a series of potential mediators in the causal chain between exposure to overdetection information and women’s subsequently reported breast screening intentions. Design: Serial multiple mediation analysis within a randomised controlled trial. Setting: New South Wales, Australia. Participants: 811 women aged 48–50 years with no personal history of breast cancer. Interventions: Two versions of a decision aid giving women information about breast cancer deaths averted and false positives from mammography screening, either with (intervention) or without (control) information on overdetection. Main outcome: Intentions to undergo breast cancer screening in the next 2–3 years. Mediators: Knowledge about overdetection, worry about breast cancer, attitudes towards breast screening and anticipated regret. Results: The effect of information about overdetection on women’s breast screening intentions was mediated through multiple cognitive and affective processes. In particular, the information led to substantial improvements in women’s understanding of overdetection, and it influenced—both directly and indirectly via its effect on knowledge—their attitudes towards having screening. Mediation analysis showed that the mechanisms involving knowledge and attitudes were particularly important in determining women’s intentions about screening participation. Conclusions: Even in this emotive context, new information influenced women’s decision-making by changing their understanding of possible consequences of screening and their attitudes towards undergoing it. These findings emphasise the need to provide good-quality information on screening outcomes and to communicate this information effectively, so that women can make well-informed decisions. Trial registration number: This study was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12613001035718) on 17 September 2013.

Breast cancer screening: It's your choice

2026-04-29T05:43:59Z

Breast cancer screening: It's your choice Hersch, Jolyn; Members of the Screening and Test Evaluation Program at The University of Sydney Why is there a decision to make about having breast cancer screening? Many people think screening for early signs of breast cancer is always a good thing. But breast screening has advantages and disadvantages. This booklet is designed to help you make an informed choice about whether you would prefer to have screening or not. Breast cancer screening decision aid for women aged 50, updated in 2017

Overdetection in breast cancer screening: Development and preliminary evaluation of a decision aid

2026-04-29T05:44:04Z

Overdetection in breast cancer screening: Development and preliminary evaluation of a decision aid Hersch, Jolyn; Jansen, Jesse; Barratt, Alexandra; Irwig, Les; Houssami, Nehmat; Jacklyn, Gemma; Thornton, Hazel; Dhillon, Haryana; McCaffery, Kirsten Objective: To develop, pilot and refine a decision aid (ahead of a randomised trial evaluation) for women around age 50 facing their initial decision about whether to undergo mammography screening. Design: Two-stage mixed-method pilot study including qualitative interviews (n=15) and a randomised comparison using a quantitative survey (n=34). Setting: New South Wales, Australia. Participants: Women aged 43–59 years with no personal history of breast cancer. Interventions: The decision aid provides evidence-based information about important outcomes of mammography screening over 20 years (breast cancer mortality reduction, overdetection and false positives) compared with no screening. The information is presented in a short booklet for women, combining text and visual formats. A control version produced for the purposes of comparison omits the overdetection-related content. Outcomes: Comprehension of key decision aid content and acceptability of the materials. Results: Most women considered the decision aid clear and helpful and would recommend it to others. Nonetheless, the piloting process raised important issues that we tried to address in iterative revisions. Some participants found it hard to understand overdetection and why it is of concern, while there was often confusion about the distinction between overdetection and false positives. In a screening context, encountering balanced information rather than persuasion appears to be contrary to people’s expectations, but women appreciated the opportunity to become better informed. Conclusions: The concept of overdetection is complex and new to the public. This study highlights some key challenges for communicating about this issue. It is important to clarify that overdetection differs from false positives in terms of its more serious consequences (overtreatment and associated harms). Screening decision aids also must clearly explain their purpose of facilitating informed choice. A staged approach to development and piloting of decision aids is recommended to further improve understanding of overdetection and support informed decision-making about screening. Decision aid development

Use of a decision aid including information on overdetection to support informed choice about breast cancer screening: A randomised controlled trial

2026-05-27T02:26:05Z

Use of a decision aid including information on overdetection to support informed choice about breast cancer screening: A randomised controlled trial Hersch, Jolyn; Barratt, Alexandra; Jansen, Jesse; Irwig, Les; McGeechan, Kevin; Jacklyn, Gemma; Thornton, Hazel; Dhillon, Haryana; Houssami, Nehmat; McCaffery, Kirsten Background: Mammography screening can reduce breast cancer mortality. However, most women are unaware that inconsequential disease can also be detected by screening, leading to overdiagnosis and overtreatment. We aimed to investigate whether including information about overdetection of breast cancer in a decision aid would help women aged around 50 years to make an informed choice about breast screening. Methods: We did a community-based, parallel-group, randomised controlled trial in New South Wales, Australia, using a random cohort of women aged 48–50 years. Recruitment to the study was done by telephone; women were eligible if they had not had mammography in the past 2 years and did not have a personal or strong family history of breast cancer. With a computer program, we randomly assigned 879 participants to either the intervention decision aid (comprising evidence-based explanatory and quantitative information on overdetection, breast cancer mortality reduction, and false positives) or a control decision aid (including information on breast cancer mortality reduction and false positives). Participants and interviewers were masked to group assignment. The primary outcome was informed choice (defined as adequate knowledge and consistency between attitudes and screening intentions), which we assessed by telephone interview about 3 weeks after random allocation. The primary outcome was analysed in all women who completed the relevant follow-up interview questions fully. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12613001035718. Findings: Between January, 2014, and July, 2014, 440 women were allocated to the intervention group and 439 were assigned to the control group. 21 women in the intervention group and 20 controls were lost to follow-up; a further ten women assigned to the intervention and 11 controls did not answer all questions on attitudes. Therefore, 409 women in the intervention group and 408 controls were analysed for the primary outcome. 99 (24%) of 409 women in the intervention group made an informed choice compared with 63 (15%) of 408 in the control group (difference 9%, 95% CI 3–14; p=0·0017). Compared with controls, more women in the intervention group met the threshold for adequate overall knowledge (122/419 [29%] vs 71/419 [17%]; difference 12%, 95% CI 6–18; p<0·0001), fewer women expressed positive attitudes towards screening (282/409 [69%] vs 340/408 [83%]; 14%, 9–20; p<0·0001), and fewer women intended to be screened (308/419 [74%] vs 363/419 [87%]; 13%, 8–19; p<0·0001). When conceptual knowledge alone was considered, 203 (50%) of 409 women in the intervention group made an informed choice compared with 79 (19%) of 408 in the control group (p<0·0001). Interpretation: Information on overdetection of breast cancer provided within a decision aid increased the number of women making an informed choice about breast screening. Becoming better informed might mean women are less likely to choose screening. Funding: Australian National Health and Medical Research Council. Main study results

The effect of information about overdetection of breast cancer on women's decision-making about mammography screening: Study protocol for a randomised controlled trial

2026-04-29T05:44:02Z

The effect of information about overdetection of breast cancer on women's decision-making about mammography screening: Study protocol for a randomised controlled trial Hersch, Jolyn; Barratt, Alexandra; Jansen, Jesse; Houssami, Nehmat; Irwig, Les; Jacklyn, Gemma; Dhillon, Haryana; Thornton, Hazel; McGeechan, Kevin; Howard, Kirsten; McCaffery, Kirsten Introduction: Women are largely unaware that mammography screening can cause overdetection of inconsequential disease, leading to overdiagnosis and overtreatment of breast cancer. Evidence is lacking about how information on overdetection affects women’s breast screening decisions and experiences. This study investigates the consequences of providing information about overdetection of breast cancer to women approaching the age of invitation to mammography screening. Methods and analysis: This is a randomised controlled trial with an embedded longitudinal qualitative substudy. Participants are a community sample of women aged 48–50 in New South Wales, Australia, recruited in 2014. Women are randomly allocated to either quantitative only follow-up (n=904) or additional qualitative follow-up (n=66). Women in each stream are then randomised to receive either the intervention (evidence-based information booklet including overdetection, breast cancer mortality reduction and false positives) or a control information booklet (including mortality reduction and false positives only). The primary outcome is informed choice about breast screening (adequate knowledge, and consistency between attitudes and intentions) assessed via telephone interview at 2 weeks postintervention. Secondary outcomes measured at this time include decision process (decisional conflict and confidence) and psychosocial outcomes (anticipated regret, anxiety, breast cancer worry and perceived risk). Women are further followed up at 6 months, 1 and 2 years to assess self-reported screening behaviour and long-term psychosocial outcomes (decision regret, quality of life). Participants in the qualitative stream undergo additional in-depth interviews at each time point to explore the views and experiences of women who do and do not choose to have screening. Ethics and dissemination: The study has ethical approval, and results will be published in peer-reviewed journals. This research will help ensure that information about overdetection may be communicated clearly and effectively, using an evidence-based approach, to women considering breast cancer screening. Trial registration number: Australian New Zealand Clinical Trials Registry ACTRN12613001035718. Study protocol