With over 150 million annual visits, U.S. emergency departments (EDs) serve as critical health care safety nets, delivering urgent and emergent care across all ages and conditions. Beyond clinical care, EDs offer valuable opportunities for conducting research focused on addressing acute clinical care issues relevant to the U.S. population. In spite of this, over the past decade less than 2% of clinical trials have been conducted in the ED.¹

The fast-paced care nature of 24/7 shift work creates a perception that the ED setting may be too pressured and overburdened to participate in or lead clinical research.² Further, the recruitment of patients who are critically unwell or during an acute emergency where emotional stress is high adds an additional challenge to recruitment and consent procedures.³ Finally, patients who seek care in the ED (on a population basis) are disproportionately impacted by social vulnerabilities such as homelessness, mental illness, and substance use comorbidities, making recruitment and longitudinal follow-up challenging.⁴ Previous longitudinal research studies in the ED setting prior to the COVID-19 pandemic have demonstrated highly variable rates of follow-up ranging from 63% to 92% at a 3-month time point.^{5, 6} While traditional research models leverage an established patient–provider relationship to identify eligible patients and support recruitment efforts, this is not possible in episodic care settings.⁷

Our team identified the need for a strategy to improve patient trust, follow-up, and retention for a clinical trial based in the ED. Here, we detail a novel strategy, coined the “Concierge Model” to address this specific challenge.

We first deployed the Concierge Model as a quality improvement measure to optimize patient follow-up and retention for a federally funded observational trial, PROTECT-APT. This study (NCT04844541) was a multicenter longitudinal case–control cohort study that sought to investigate the physiological and immunological characteristics of patients (and uninfected close contacts) who presented to the ED with COVID-19 and influenza-like illness.⁸ We enrolled 196 participants in two urban ED settings in Baltimore, Maryland, from November 2021 to December 2023. Comprehensive clinical data were collected at the time of presentation and at interval follow-ups up to 90 days (eight total, four in person, and four remote). In-person visits included blood and nasal sampling, lung ultrasounds, physical examinations, vital signs, and questionnaires. During remote visits, participants self-collected nasal swabs and blood samples using the Tasso microsampling device.⁹ Daily symptom questionnaires were also sent for the first 2 weeks. Given the level of engagement postdischarge, study staff used text message reminders before each follow-up and sample collection. A total of seven coordinators and four ED faculty members supported the study.

During the study implementation period, four participants withdrew in the first 2 weeks, and only 42% of the first 20 participants completed the study, with 33% lost to follow-up (defined as not completing the Day 90 research activities) and 25% voluntarily withdrawing. We were concerned that this was likely due to the large number of study events and the impersonal nature of our communication strategy.

To address this challenge, we launched an innovative Concierge Model with the explicit goal of improving study completion rates via increasing rapport between the study coordinator and the subject. In this approach, each research coordinator became a dedicated “concierge” for each participant they enrolled, managing all communication to ensure consistency and accountability. The expressed goal emphasized to staff at the start of the study was to enhance two-way communication and decrease likelihood of subjects withdrawing or being lost to follow-up. Practically, concierge coordinators entered the study contact phone number into participants’ phones and confirmed their details at enrollment, establishing a reliable connection from day one. Concierges made reminder calls 1 week and 1 day before each follow-up activity and were available from 8:00 a.m. to 10:00 p.m., Monday through Friday, for any ad hoc questions and support subjects requested. Qualitatively, our team observed that individualized and customized interactions enhanced subject engagement, streamlining communication between the study team and the subject. In addition, all in-person follow-up visits were conducted by that subject's personal concierge.

Following implementation of the Concierge Model, rates of questionnaire completion, remote sample collection, and in-person follow-up visits significantly improved. For the 176 participants for whom the Concierge Model was made available, study completion rate increased from 42% to 62% (29% lost to follow-up, 9% voluntary withdrawal). Although this rate fell below our ideal targets, the model's implementation significantly improved meaningful trial outcomes. The study faced challenging time points and was conducted during the peak of the COVID-19 pandemic, which notably hindered clinical trial completion across health care settings, including outside of ED acute care.¹⁰

Challenges encountered with implementing the Concierge Model included workload imbalance and staff turnover. To address this, participants were evenly assigned during enrollment, and when staff left the study team, participants were redistributed (coordinators with fewer participants took on new enrollees and departing staff introduced participants to their new concierge via call or follow-up). Each assigned concierge managed these additional participants until Day 90 completion.

The ED captures often-missed populations and must be engaged in research to ensure representative participation. Executing clinical trials in the ED does introduce unique challenges. Given that high rates of attrition represent one of the largest threats to robust clinical trials in the ED, the Concierge Model is an innovative solution that increases rates of retention in longitudinal clinical trials.

CONFLICT OF INTEREST STATEMENT

The authors declare no conflicts of interest.