Trauma Communications Center Coordinated Severity-Based Stroke Triage: Protocol of a Hybrid Type 1 Effectiveness-Implementation Study

Abstract

Background: Mechanical thrombectomy (MT) can improve the outcomes of patients with large vessel occlusion (LVO), but a minority of patients with LVO are treated and there are disparities in timely access to MT. In part, this is because in most regions, including Alabama, the emergency medical service (EMS) transports all patients with suspected stroke, regardless of severity, to the nearest stroke center. Consequently, patients with LVO may experience delayed arrival at stroke centers with MT capability and worse outcomes. Alabama's trauma communications center (TCC) coordinates EMS transport of trauma patients by trauma severity and regional hospital capability. Our aims are to develop a severity-based stroke triage (SBST) care model based on Alabama's trauma system, compare the effectiveness of this care pathway to current stroke triage in Alabama for improving broad, equitable, and timely access to MT, and explore stakeholder perceptions of the intervention's feasibility, appropriateness, and acceptability. Methods: This is a hybrid type 1 effectiveness-implementation study with a multi-phase mixed methods sequential design and an embedded observational stepped wedge cluster trial. We will extend TCC guided stroke severity assessment to all EMS regions in Alabama; conduct stakeholder interviews and focus groups to aid in development of region and hospital specific prehospital and inter-facility stroke triage plans for patients with suspected LVO; implement a phased rollout of TCC Coordinated SBST across Alabama's six EMS regions; and conduct stakeholder surveys and interviews to assess context-specific perceptions of the intervention. The primary outcome is the change in proportion of prehospital stroke system patients with suspected LVO who are treated with MT before and after implementation of TCC Coordinated SBST. Secondary outcomes include change in broad public health impact before and after implementation and stakeholder perceptions of the intervention's feasibility, appropriateness, and acceptability using a mixed methods approach. With 1200 to 1300 total observations over 36 months, we have 80% power to detect a 15% improvement in the primary endpoint. Discussion: This project, if successful, can demonstrate how the trauma system infrastructure can serve as the basis for a more integrated and effective system of emergency stroke care.

Keywords: delivery of health care; emergency medical service; implementation science; large vessel occlusion; mechanical thrombectomy; mixed methods research; prehospital care; trauma communications centers.

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Copyright © 2021 Gropen, Ivankova, Beasley, Hess, Mittman, Gazi, Minor, Crawford, Floyd, Varner, Lyerly, Shoemaker, Owens, Wilson, Gray and Kamal.

Figures

Figure 1

Alabama EMS Regions and Stroke Centers. The Alabama stroke system has 80 stroke centers. Level III centers (green dots) are acute stroke-ready hospitals, level II centers (blue dots) are primary stroke centers, and Level I centers (yellow dots) are comprehensive stroke centers. See text for details regarding primary stroke centers that are currently thrombectomy-capable. Map Source: ADPH.

Figure 2

Study flowchart of hybrid type 1 effectiveness-implementation study with a multi-phase mixed methods sequential design and an embedded observational stepped wedge cluster trial.

Figure 3

Flow of patients during study. The study will include prehospital patients entered into the stroke system by EMS with an EMSA ≥ 4. Patients with a time last known well (LKW) > 24 h or those who respond only to pain or who are unresponsive will be excluded. During the standard triage period, patients meeting study entry criteria will be transported to the closest stroke center with capacity. During TCC Coordinated SBST, patients will be routed by TCC directly to a MTC (including comprehensive stroke centers and thrombectomy-capable primary stroke centers) if additional transport time complies with region-specific transport time limits and will not preclude use of tPA. Otherwise, TCC will coordinate transport to the closest stroke center of any level and initiate a region and hospital specific plan to expedite inter-facility transfer to a MTC for appropriate patients.

Figure 4

Data sources. (1) Expanded LifeTrac data entry on all stroke system patients with embedded LifeTrac data collection by TCC on study patients to both guide and document the prehospital triage process in real-time; (2) Study patient ED and hospital data entered by stroke coordinators into an ADPH REDCap database, and (3) System level data captured by ADPH's Recording of Emergency Medical Services Calls and Urgent-care Environment electronic Patient Care Reports (ADPH RESCUE ePCR).

Figure 5

Five year timeline. Stepped wedge cluster trial with each EMS region serving as a cluster. During Standard Triage periods, we will implement TCC Guided EMSA but continue current triage to the nearest stroke center of any level and conduct focus groups and interviews to aid in the development of region and hospital specific SBST plans. During the Train periods, we will conduct regional educational symposia and implement SBST plans. During TCC Coordinated SBST periods TCC will guide EMS in performance of the EMSA and coordinate SBST and we will conduct stakeholder surveys and interviews to assess context-specific perceptions of the intervention.