Abstract A136: Design and interim review of a pragmatic stepped wedge cluster randomized clinical trial testing behavioral economic implementation strategies to increase supplemental breast MRI screening among patients with extremely dense breasts
Authors: Mack Elizabeth , Blumenthal Daniel , Perez Claudia Fernandez , Beidas Rinad , Bekelman Justin , Asch David A. , Bauer Anna-Marika , Buttenheim Alison M. , Conant Emily F. , Doucette Abigail , Fayanju Oluwadamilola M. , Gabriel Peter , Guerra Carmen , Nunes Linda W. , Plag Martina , Rendle Katharine A. , Shelton Rachel C. , Shulman Lawrence , Ware Sue , Wheeler Bernadette C. , Wileyto Paul , Schnoll Robert , McCarthy Anne Marie 
Published: September 2024

Abstract
INTRODUCTION Supplementing routine screening mammography with breast MRI can significantly increase cancer detection among women with extremely dense breasts, but breast MRI is not widely utilized. At Penn Medicine in 2021, only 8% of women with extremely dense breasts completed supplemental breast MRI screening, with even lower completion among Black women (3%). METHODS We designed a pragmatic trial to evaluate whether sending “nudges” (messages informed by behavioral economics) promoting breast MRI to patients, clinicians, or both increases breast MRI utilization among women with extremely dense breasts. Given baseline inequities, we also sought to assess whether nudges could reduce racial differences in MRI screening rates. This trial is being performed in a state with newly mandated insurance coverage for supplemental MRI screening for patients with extremely dense breasts. Patients aged 40-74 with extremely dense breasts reported on non-actionable mammograms are identified and independently randomized to receive a patient nudge or not. Patient nudges are delivered via text message following confirmation of identify and interest. Prior to launching the trial, rapid cycle approaches (RCAs) tested a set of messages in a diverse patient sample to optimize and de-risk nudge content. Clinicians receive nudges embedded within the mammogram report or through electronic health record in-basket messages. The primary outcome of the trial is ordering and/or scheduling of breast MRI within 6 months of a mammogram. Enrollment numbers and preliminary data on the implementation of the trial has been collected. RESULTS In 8 months, 990 women with extremely dense breasts have been enrolled. The study population currently includes 618 White women, 170 Black women, and 202 women of other races. In total, 36% of women in the patient nudge arm opted to receive the nudge. Patient nudge reception was 35% for White patients and 38% for Black patients. Additionally, 18% of women in the patient nudge arm opted out of receiving the nudge, with 18% of White patients and 22% of Black patients declining the nudge. The provider nudge was successfully delivered 97% of the time. Overall, MRIs have been ordered for about 22% of patients across all study arms. When stratified by race, the order rate was 25% for White patients compared to 16% for Black patients. While follow-up periods have not been completed for many patients, MRIs have been scheduled for 13% of all patients. CONCLUSIONS Despite laws mandating insurance coverage of supplemental screening and emerging evidence of the benefits of supplemental breast MRI for women with extremely dense breasts, there is still inequity in utilization. This trial aims to determine whether nudges can help reduce this existing inequity. Our early results suggest that patient acceptance of text message nudges was similar for White and Black patients. We eagerly await full analyses to determine the efficacy of nudges in increasing uptake and in improving equity of MRI screening among women with extremely dense breasts.
Citation Format: Elizabeth Mack, Daniel Blumenthal, Claudia Fernandez Perez, Rinad Beidas, Justin Bekelman, David A. Asch, Anna-Marika Bauer, Alison M. Buttenheim, Emily F. Conant, Abigail Doucette, Oluwadamilola M. Fayanju, Peter Gabriel, Carmen Guerra, Linda W. Nunes, Martina Plag, Katharine A. Rendle, Rachel C. Shelton, Lawrence Shulman, Sue Ware, Bernadette C. Wheeler, Paul Wileyto, Robert Schnoll, Anne Marie McCarthy. Design and interim review of a pragmatic stepped wedge cluster randomized clinical trial testing behavioral economic implementation strategies to increase supplemental breast MRI screening among patients with extremely dense breasts [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A136.