Emergency department crowding can be addressed as a problem of input, throughput and output, and understood from the perspective of the patient and health system. One option that many high volume and academic medical centers have explored is a ‘split-flow’ approach, which disrupts the traditional approach where every patient follows the same path through ED intake, triage, treatment and discharge. Split flow models have been shown to meaningfully reduce patient length of stay, door-to-provider times and left-without-being-seen (LWBS) rates.¹

The Split Flow model is also known as the “Provider-in-Triage” model, and occurs when a physician leads the patient intake process rather than a nurse. Split flow allows the physician to immediately assess patient acuity and determine the track they’ll take through the ED, as well as order testing, imaging and medication at intake, rather than after the waiting period.² Patients with an ESI of 4 and 5 are traditionally placed on a fast track, where they quickly receive treatment and orders, and the patients of ESI 1 and 2 are placed on the critical care path. ESI levels of 3 are sometimes difficult to place in a pure split-flow model, as some require treatment in a traditional hospital bed, and some do not. 

After intake, patients are sorted into different tracks, such as high acuity or critical care, or mid-track or fast track. The type of track a patient enters determines where in the ED they’ll receive care, how long they wait and how long their length of stay will be. Low acuity patients are placed on a fast track with quicker access to care and discharge, and are less likely to LWBS, and patient beds are reserved for complex patients needing more intensive care and eventual transfer to a hospital or other healthcare facility.

Large hospitals and academic medical centers often implement split models at certain times of day and for certain levels of patient volumes, especially during periods of low congestion.² Split flow cannot be implemented as a simple replacement of a nurse with a physician, but must also include a multi-disciplinary staff (e.g. phlebotomists, scribe, EKG technician and registration staff). There are several hypotheses as to why the split flow model leads to better outcomes. One is that the provider-in-triage leads to faster disposition and discharge decisions. Second, split flow also reduces readmission rates through more direct treatment and discharge orders. Lastly, the model reduces waiting room congestion and improves patient satisfaction with their speed of care.³ 

EDs who have implemented split flow models have also experienced issues, especially when they’re used in periods of high congestion. Split flow models may lead to increased workload for physicians and their teams when triage team members have multiple roles. Split flow models also require a re-designed intake process and hospital footprint that accommodates varying ESI levels and patient bed needs.

The split flow concept is an effective intake and throughput process change, and has been demonstrated to improve throughput rates and patient satisfaction.

References

1. Arya, R., Wei, G., McCoy, J. V., Crane, J., Ohman-Strickland, P., & Eisenstein, R. M. (2013). Decreasing Length of Stay in the Emergency Department With a Split Emergency Severity Index 3 Patient Flow Model. Academic Emergency Medicine, 20(11), 1171–1179. https://doi.org/10.1111/acem.12249
2. David Gomez, J. C., Cochran, A. L., Patterson, B. W., & Zayas-Cabán, G. (2024). Evaluation of a Split Flow Model for the Emergency Department. Manufacturing & Service Operations Management, 26(3), 911–930. https://doi.org/10.1287/msom.2022.0003
3. Garrett, J. S., Berry, C., Wong, H., Qin, H., & Kline, J. A. (2018). The effect of vertical split-flow patient management on emergency department throughput and efficiency. The American Journal of Emergency Medicine, 36(9), 1581–1584. https://doi.org/10.1016/j.ajem.2018.01.035