A mixed-methods evaluation of multilevel barriers and facilitators to inform implementation strategies for advancing equitable clinical trial accrual in a large comprehensive cancer center

Introduction: Multilevel interventions and implementation strategies at the system, provider, and patient levels can support clinical trial enrollment. This study examines processes, facilitators, and barriers to clinical trial enrollment across a large comprehensive cancer center to inform interventions and identify opportunities for implementation strategies to sustain equitable trial participation. Methods : Guided by the Consolidated Framework for Implementation Research (CFIR), we used a mixed-methods design to survey and interview oncology and hematology providers from September 2024 to April 2025. Providers at USC Norris Comprehensive Cancer Center's main medical campus and satellite clinics completed surveys and in-depth interviews that assessed their experiences with trial enrollment, including beliefs, attitudes, and knowledge about clinical trials; workflow and organizational culture; and patient barriers. Survey data were summarized using descriptive statistics, and interview transcripts were coded using CFIR to identify key implementation determinants. Results: Among survey participants (n=49), 69% practiced at the main campus and 31% at satellite clinics. Although 96% viewed clinical trials as important to patient care, 45% indicated gaps in knowledge of trial accrual. Inner setting barriers differed by site, with 74% of providers at the main campus compared to 20% at satellite clinics citing limited staffing support for clinical trials (p=0.003). Outer setting barriers showed less variation, with 64% of providers at the main campus and 53% at satellite clinics reporting limited language translation resources (p=0.44). Qualitative interviews (n=15) reinforced these CFIR domains; limited access to research coordinators, time constraints, and language translation emerged as key barriers. Provider motivation and interest in trials accrual training were identified as key facilitators to optimize trial enrollment. Discussion : Barriers to optimal clinical trial recruitment include gaps in provider knowledge, staffing limitations, and insufficient language resources, all of which may constrain equitable enrollment. Despite these challenges, providers remained motivated to offer trials to their patients. Advancing enrollment requires co-designed solutions with providers and clinic teams to address system level and patient barriers. Targeted interventions - such as provider training, enhanced access to trial information, and translation services - may improve inclusive enrollment.