Implementation Fidelity Of A Complex Behavioral Intervention To Prevent Diabetes Mellitus In Two Safety Net Patient-Centered Medical Homes In New York City

BackgroundIt is critical to assess implementation fidelity for complex interventions to understand the reasons for their success or failure. However, few interventions systematically report implementation evaluation. Therefore, we conducted a concurrent process evaluation of CHORD (Community Health Outreach to Reduce Diabetes), a pragmatic, cluster-randomized, controlled trial to test the impact of a Community Health Workers (CHW) led, health coaching intervention on preventing incident type 2 Diabetes Mellitus (DM). MethodsThe study population included primary care (PC) patients with prediabetes at 2 safety-net hospitals - VA NY Harbor and Bellevue (BH). PC teams were randomized to receive the one-year intervention or usual care. Of the 559 patients in the intervention group to date, 79.4% completed an intake survey, constituting the analytic sample for fidelity assessment. The Conceptual Framework for Implementation Fidelity (CFIF) was applied to measure implementation fidelity and factors moderating fidelity of four core intervention components: patient goal setting, education topic coaching, PC visits, and referrals to address social determinants of health, using descriptive statistics and regression models.ResultsBH contributed 60.0% of the sample and VA contributed 40.0%. Content adherence was high for three components with nearly 80.0% of patients setting >1 goal, having >1 PC visit and receiving coaching on >1 education topic. Only 45.0% patients received >1 referral. After adjusting for patient gender, language, race, ethnicity, and age, the study site moderated adherence to goal setting (77.4% BH vs. 87.7% VA), educational coaching (78.9% BH vs. 88.3% VA), number of successful CHW-patient encounters (6 BH vs 4 VA) and percent of patients receiving all four components (41.1% BH vs. 25.7% VA). ConclusionsThe CFIF enabled analysis of implementation fidelity of a complex, behavioral intervention. The fidelity of CHORD implementation varied across its four components and was moderated by site. Despite implementation in a research setting, interventions may not completely adhere to their core components, which can influence outcomes. Our study emphasizes the importance of examining implementation fidelity of interventions and of assessing moderating factors. Our study also empirically tested the CFIF using quantitative concurrent intervention fidelity evaluation.Trial registration: The trial was registered with ClinicalTrials.gov on 12/30/2016 and the registration number is NCT03006666. The link to trial registration is: https://clinicaltrials.gov/ct2/show/NCT03006666