Format matters: Digital vs print delivery of a job retention intervention during breast cancer therapy.

11060 Background: Talking to Employers and Medical Staff about Work (TEAMWork) is an English/Spanish intervention, delivered as a booklet or mobile app, which was developed to improve work outcomes among women undergoing (neo)adjuvant breast cancer therapy. TEAMWork provides education on work accommodations based on vocational rehabilitation principles, employer negotiation strategies, symptom self-management tools, and guidance on communicating with clinicians to enhance support (e.g., obtain work documentation). Here we present data on predictors of intervention use during systemic therapy from an ongoing randomized controlled trial comparing the TEAMWork app to the booklet. Methods: Eligible participants were women aged 18-65 years with stage I-III breast cancer who spoke English and/or Spanish, were employed pre-diagnosis, and undergoing or planning to undergo systemic (neo)adjuvant chemotherapy. Patients were recruited between October 2021 – March 2025 from multiple New York City sites. Data on socio-demographics, work characteristics, and intervention use were collected through patient surveys at baseline and after completion of chemotherapy. Multivariable logistic regression was used to assess predictors of intervention use during systemic therapy. Results: Of 372 participants (89% English; 11% Spanish), 54% identified as White, 17% Black, and 20% Hispanic/Latina. The mean age was 48 years. 70% were college-educated. All were employed at diagnosis, but only 77% were actively working (e.g., not on leave) at baseline. Participants worked in various occupations: managerial/professional (50%), sales/technical/administrative support (24%), service providers (21%), arts/media/athletics (5%), and operators/fabricators/laborers (1%). All participants received chemotherapy, with 53% starting therapy before the baseline survey. Slightly over half of participants (53%) reported using TEAMWork during systemic therapy; 120/187 (64%) in the mobile app arm and 76/185 (41%) in the booklet arm. In multivariable analysis, assignment to the mobile app arm was positively associated with intervention use during treatment (OR 2.54, 95% CI 1.61-4.05, p<.001). However, age, race, ethnicity, language, US-born (yes/no), educational attainment, occupational category, and chemotherapy initiation prior to randomization were not independently associated with intervention use. Conclusions: After adjusting for sociodemographic, occupational, and treatment-related characteristics, participants randomized to the mobile app arm had more than double the odds of using TEAMWork compared to those in the booklet arm. These findings underscore the importance of delivery format in the design of supportive interventions. Although mobile app development can be time- and resource-intensive, this approach may offer meaningful advantages in promoting patient engagement during therapy.