Abstract P2-05-03: Perceived Guideline Clarity & Deferral to Patient Preferences impact guideline concordant care for breast cancer screening in women age 40-49
Authors: Nadler Michelle , Corrado Ann Marie , Wilson Brooke E. , Desnoyers Alexandra , Amir Eitan , Ivers Noah , Desveaux Laura 
Published: March 2023

Background: Canadian and US Task Forces recommend against routine mammography screening for women age 40-49 at average breast cancer risk on the basis that harms outweigh the benefits. Both cite the importance of supporting women’s individualized decisions based on the relative value placed on potential benefits and harms of screening (2, 4). Population-based data reveal that screening rates in this age group are influenced by the woman’s primary care provider (PCP), suggesting some providers refer more often than others. This highlights the need to explore PCP perspectives on screening and how this informs clinical behaviour.

Methods: Qualitative semi-structured interviews were performed by phone with PCPs in Ontario, Canada. Interviews were structured using the Theoretical Domains Framework (TDF) to explore determinants (barriers/facilitators) of three screening-related behaviours: 1) conducting a risk assessment; 2) discussion regarding benefits and harms; and 3) making a decision regarding referral for mammographic screening.

Analysis: Interviews were transcribed and analyzed iteratively until saturation was reached. Two independent researchers coded all transcripts deductively both by behaviour and according to TDF domain. Findings that did not fit within a TDF code were coded inductively. Data were then grouped by screening behaviour and the associated codes were used to generate descriptive narratives of the determinants influencing PCP behaviour.

Results: Eighteen physicians (mean age 48, 72% identified female) were interviewed. Table 1 outlines the determinants of the three screening behaviours. Analysis of inductive codes revealed two key contextual themes that influenced behaviours and moderated TDF codes: perceived guideline clarity (a lack of clarity on which behaviours (if any) were guideline-concordant) and deferral to patient preference (patient decision regarding screening without a complete discussion of benefits and harms). PCPs who perceived that the guidelines stated definitively that screening was not recommended had improved knowledge of harms and stronger beliefs about capabilities to educate patients about why screening was not recommended routinely. Deferral to patient preference seemed to occur when PCP’s knowledge was low and/or if they were impacted by experience of a younger woman diagnosed with breast cancer, which often led to anticipated regret (TDF domain: emotion).

Discussion/Conclusion: Low knowledge related to formal breast cancer risk assessment, combined with a tendency to over-estimate benefits of screening relative to harms could explain some inappropriate variation in practice. All 3 PCP screening behaviours appeared to be affected by both perceived guideline clarity and deferral to patient preferences. These may all be effective targets for future interventions to address variation in care.

Table 1: Unique Barriers and Facilitators of Three Screening Behaviours

Citation Format: Michelle Nadler, Ann Marie Corrado, Brooke E. Wilson, Alexandra Desnoyers, Eitan Amir, Noah Ivers, Laura Desveaux. Perceived Guideline Clarity & Deferral to Patient Preferences impact guideline concordant care for breast cancer screening in women age 40-49 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-05-03.