PROJECT SUMMARY Background: Low back pain (LBP) is common, disabling and costly. Recent American College of Physicians guidelines recommend nonpharmacologic treatments (e.g., spinal manipulation, heat, massage, and acupuncture) as safe and effective first-line approaches for LBP. However, these treatments are most commonly provided to middle- to high- income predominantly white communities, with limited access for low income racially-diverse patients. Chiropractic care, which includes spinal manipulation, is a prototypical example of this care gap; few doctors of chiropractic (DCs) are integrated into medical settings, and primary care providers (PCPs) rarely refer to community-based DCs. Goals and Objectives: Dr. Roseen?s long-term career objective is to become an independent investigator studying the effectiveness and implementation of LBP treatments for underserved populations. This K23 career development award will allow Dr. Roseen to gain advanced skills in conducting pragmatic clinical trials that can assess the real-world effectiveness of LBP treatments and to become competent in the development and assessment of implementation strategies. Career Development Activities: The K23 application will provide structured didactic and hands-on training that will build on Dr. Roseen?s training in chiropractic and epidemiology, through experience and education in process mapping, qualitative methods, implementation strategies, outcome measurement in pragmatic trials, and advanced statistical analyses. The plan will engage Dr. Roseen in robust training activities including mentorship, coursework, research projects, publishing and presenting, workshops and seminars, grant-writing, and responsible conduct of research. Mentors: Dr. Roseen?s mentorship team consists of accomplished scientists from clinical research, health services research, epidemiology, biostatistics, medical anthropology, implementation science, and primary care. Environment: Dr. Roseen will benefit from a comprehensive research training program based at Boston University (BU), Boston Medical Center, BU Clinical Epidemiology Research and Training Unit, BU Center for Improvement and Implementation Science, and BU Clinical and Translational Science Institute. Research: Dr. Roseen?s proposed K23 research project will address the limited availability of nonpharmacologic treatments, using chiropractic care as an exemplar, in primary care settings. Dr. Roseen will first engage key stakeholders through process mapping and analysis (Aim 1a). Secondly, qualitative methods will be used to identify facilitators and barriers of PCP-DC referrals (Aim 1b). He will then design and pilot a multi-level implementation strategy in three community health centers based in underserved neighborhoods in Boston (Aim 2). This award will prepare Dr. Roseen to submit a future competitive grant application for a multi-site hybrid implementation and effectiveness trial of chiropractic care for LBP in underserved communities.