Health Services and Economic Impacts of the Limit of Detection in Emergency Department (LEGEND) Rule-Out Strategy in Australian Emergency Departments: A Stepped-Wedge Cluster Randomised Trial.

Objective: This study aimed to describe healthcare utilisation and costs associated with the assessment of suspected acute coronary syndrome (ACS) under standard care and to compare these outcomes with the Limit of Detection in Emergency Department (LEGEND) strategy, an accelerated diagnostic pathway identifying low-risk patients using a single highly sensitive troponin (hs-cTnI).

Method: A stepped-wedge cluster randomised trial was conducted in four Queensland hospitals. Each transitioned from standard care (2016 ACS guidelines) to the LEGEND intervention at randomised intervals. Data were collected for index presentations and 6-month outcomes.

Results: Data were collected from 5347 patients in the standard care phase and 4597 in the LEGEND intervention phase. The intervention reduced mean ED length of stay (-72.0 min, 95% CI: -85.0 to -59.0 min) and inpatient admissions (-2.3%, 95% CI: -4.2% to -0.4%). For low-risk patients, the intervention further reduced ED length of stay (-97.0 min, 95% CI: -120.5 min to -73.5) and inpatient admissions (-4.2%, 95% CI: -6.9 to -1.6%). Exercise stress testing (EST) utilisation decreased by 3.6% (95% CI: 2.3%-4.9%) overall and 7.7% (95% CI: 5.0%-10.4%) among low-risk patients during the intervention phase. Total costs decreased from $6849 to $5794 per patient overall, saving $1055 per patient and from $2847 to $2129 per low-risk patient, saving $718 per patient.

Conclusions: The LEGEND strategy demonstrated reduced resource utilisation and costs compared to guideline-based ACS assessment, particularly for low-risk patients. Widespread adoption could improve the efficiency and cost-effectiveness of ACS assessment in the healthcare system.