Abstract
BACKGROUND: We implemented a centralized colorectal cancer (CRC) screening program with navigation to follow-up colonoscopy for community health center (CHC) patients with positive stool-based test screening results. Navigation increased six-month colonoscopy completion by 24 percentage points compared with usual care. Here, we describe how we applied a functions and forms framework alongside causal loop diagramming (CLD) to understand the effectiveness of our navigation program and explore its potential for implementation in other settings. METHODS: We first identified barriers to colonoscopy completion in our primarily rural sample and detailed the navigation services provided. Next, we classified our program into core functions (key components contributing to success) and corresponding forms (elements detailing how the functions were carried out and adapted to the local context). To inform classification, we reviewed program documentation (e.g., implementer notes, call logs, and protocol). We refined findings collaboratively in workshops with the navigation team and leadership. We also conducted CLD sessions to document and visualize how the functions addressed the problems affecting colonoscopy completion, refining our list of functions and forms based on these findings. RESULTS: We identified nine key functions of our navigation program - bridging across patients, providers, and systems; reaching and engaging patients; building rapport and trust; identifying and alleviating concerns; developing readiness and self-efficacy; linking to resources; monitoring progress; enhancing communication; and providing consistent, high-quality navigation services. We documented 29 distinct forms operationalizing these functions within our local context (e.g., motivational interviewing to address barriers and support self-efficacy). We developed a causal loop diagram to explore interactions among the multi-level factors affecting colonoscopy completion and how the navigation program addressed those factors. DISCUSSION: Organizing functions and forms clarified core elements of success and aspects adaptable for scale-up or replication across different contexts. CLD provided insights into how the functions contributed to the program's success and helped identify additional forms. Findings will guide efforts to translate this navigation model to varied contexts. STUDY REGISTRATION: ClinicalTrials.gov Identifier: NCT04406714.