March 13, 2023

✪ A sequential, multiple assignment randomized trial comparing web-based education to mobile video interpreter access for improving provider interpreter use in primary care clinics: the mVOCAL hybrid type 3 study protocol


K. Casey Lion, Chuan Zhou, Paul Fishman, Kirsten Senturia, Allison Cole, Kenneth Sherr, Douglas J. Opel, James Stout, Carmen E. Hazim, Louise Warren, Bonnie H. Rains, & Cara C. Lewis.

University of Washington affiliated authors are displayed in bold.

✪ Open Access

Published: March 2023

Read the full text in the open access journal Implementation Science



Individuals who use a language other than English for medical care are at risk for disparities related to healthcare safety, patient-centered care, and quality. Professional interpreter use decreases these disparities but remains underutilized, despite widespread access and legal mandates. In this study, we compare two discrete implementation strategies for improving interpreter use: (1) enhanced education targeting intrapersonal barriers to use delivered in a scalable format (interactive web-based educational modules) and (2) a strategy targeting system barriers to use in which mobile video interpreting is enabled on providers’ own mobile devices.


We will conduct a type 3 hybrid implementation-effectiveness study in 3–5 primary care organizations, using a sequential multiple assignment randomized trial (SMART) design. Our primary implementation outcome is interpreter use, calculated by matching clinic visits to interpreter invoices. Our secondary effectiveness outcome is patient comprehension, determined by comparing patient-reported to provider-documented visit diagnosis. Enrolled providers (n = 55) will be randomized to mobile video interpreting or educational modules, plus standard interpreter access. After 9 months, providers with high interpreter use will continue as assigned; those with lower use will be randomized to continue as before or add the alternative strategy. After another 9 months, both strategies will be available to enrolled providers for 9 more months. Providers will complete 2 surveys (beginning and end) and 3 in-depth interviews (beginning, middle, and end) to understand barriers to interpreter use, based on the Theoretical Domains Framework. Patients who use a language other than English will be surveyed (n = 648) and interviewed (n = 75) following visits with enrolled providers to understand their experiences with communication. Visits will be video recorded (n = 100) to assess fidelity to assigned strategies. We will explore strategy mechanism activation to refine causal pathway models using a quantitative plus qualitative approach. We will also determine the incremental cost-effectiveness of each implementation strategy from a healthcare organization perspective, using administrative and provider survey data.


Determining how these two scalable strategies, alone and in sequence, perform for improving interpreter use, the mechanisms by which they do so, and at what cost, will provide critical insights for addressing a persistent cause of healthcare disparities.

Trial registration


**This abstract is posted with permission under the Creative Commons Attribution 4.0 International License**