Evidence Hub

Low-Acuity Patients Delay High-Acuity Patients in EDs

Danqi Luo, Mohsen Bayati, Erica L. Plambeck, Michael Aratow

RePEc: Research Papers in Economics, 2021

1 citation

Abstract

This paper provides evidence that the arrival of an additional low-acuity patient substantially increases the wait time to start of treatment for high-acuity patients, contradicting the long-standing prior conclusion in the medical literature that the effect is "negligible." Whereas the medical literature underestimates the effect by neglecting how delay propagates in a queuing system, this paper develops and validates a new estimation method based on queuing theory, machine learning and causal inference. Wait time information displayed to low-acuity patients provides a quasi-randomized instrumental variable. This paper shows that a low-acuity patient increases wait times for high-acuity patients through: pre-triage delay; delay of lab tests ordered for high-acuity patients; and transition delay when an ED interrupts treatment of a low-acuity patient in order to treat a high-acuity patient. Hence high-acuity patients' wait times could be reduced by: reducing the standard deviation or mean of those transition delays, particularly in bed-changeover; providing vertical or "fast track" treatment for more low-acuity patients, especially ESI 3 patients; standardizing providers' test-ordering for low-acuity patients; and designing wait time information systems to divert (especially when the ED is highly congested) low-acuity patients that do not need ED treatment.

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free