Impact of Ten Second Triage vs. Sieve on Triage Performance in Simulated Mass-Casualty Incidents

Impact on Triage Performance in Simulated Multiple-casualty Situations of TST (Ten Second Triage) Versus Sieve

This study will compare two emergency triage algorithm - Ten Second Triage (TST) versus Sieve - to see which one works better during simulated mass-casualty incidents. Triage is the process of quickly deciding which patients need immediate care when there are many injured people. Making fast and accurate decisions is essential in these situations.

Ambulance professionals and students in French-speaking Switzerland will be invited to take part. Participants will be randomly assigned to use either the TST method or the Sieve method. After a short introduction to the assigned method, each participant will complete two computer-based simulation scenarios involving 17 injured patients each (one scenario with penetrating injuries and one with blunt injuries). The simulated patients' conditions will change over time, similar to real-life emergencies using a physiological validated simulator (HUMAn).

The main goal is to measure how accurately participants identify patients who need immediate treatment. For each correct triage decision, participants receive one point. A total score will be calculated across both scenarios. If a sufficient sample size could be reached, a mixed effect logistic regression model will be generated to answer to research question.

The study will also measure how long participants take to make triage decisions, how often patients are over-triaged or under-triaged, and how easy participants find the method to use.

The results will help determine which triage method may be more effective for use by ambulance personnel during major incidents.

Study Overview

• Status: Completed
• Conditions: Mass Casualty Incidents
• Intervention / Treatment: Other: Sieve triage algorithm; Other: Ten Second Triage algorithm

• Study Type: Interventional
• Enrollment (Actual): 201
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Canton of Geneva
    • Geneva, Canton of Geneva, Switzerland, 1213
      • École supérieure de soins ambulanciers (ESAMB)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Prehospital care professionals (e.g., ambulance personnel) or paramedic students
• Practicing or training in French-speaking Switzerland
• Likely to be involved in the management of major incidents or mass-casualty events
• Provided informed consent to participate

Exclusion Criteria:

• Participants who answered "No" to the statement confirming that their questionnaire responses reflect their usual personal practice
• Participants who did not view the instructional video of the assigned triage algorithm (time spent on the video page is recorded), except participants randomized to the Sieve arm who routinely use the Sieve algorithm in their clinical practice

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Sieve; The control group will be provided with the Sieve triage algorithm.	Other: Sieve triage algorithm; Sieve (NARU) triage algorithm is a structured primary triage method used during mass-casualty incidents, developed and promoted by the National Ambulance Resilience Unit (NARU). It is designed to rapidly sort large numbers of patients based on simple physiological criteria. The Sieve algorithm follows a stepwise assessment focusing on the ability to walk, breathing status and rate, and circulation (including signs of life-threatening hemorrhage). Patients are then assigned to standard triage categories (immediate, urgent, delayed, or deceased). Sieve emphasizes consistency and reproducibility of triage decisions and is widely used in prehospital disaster response and training to support safe prioritization when resources are limited.
Experimental: TST; The experimental group will be provided with the Ten Seconde Triage algorithm	Other: Ten Second Triage algorithm; Ten Second Triage (TST) is a rapid primary triage algorithm designed for use in mass-casualty incidents. It aims to allow rescuers to assess and categorize a patient in approximately 10 seconds based on a small number of immediately observable clinical signs. The algorithm focuses on key life-saving indicators such as ability to walk, presence of major external bleeding, airway status, breathing effectiveness, and level of consciousness. Based on these findings, patients are assigned to standard triage categories (e.g., immediate, urgent, delayed, or deceased). TST prioritizes speed and simplicity to support rapid decision-making when resources are limited and many victims require simultaneous assessment.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Triage accuracy (triage score)	Triage accuracy is defined as the proportion of correct triage decisions made by each participant across two simulated mass-casualty scenarios (34 patients in total). For each simulated patient, participants receive: 1 point for a correct triage decision (0 points for an incorrect decision). A triage decision is considered correct if the assigned priority category matches the simulated patient's expected clinical evolution based on the HUMAn dynamic simulation model (i.e., correct identification of patients requiring immediate treatment versus those who do not, including appropriate classification of deceased patients). The primary endpoint is the total triage score per participant (range 0-34), calculated by summing correct decisions across both scenarios.	Through study completion, an average of 1 hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Triage duration	Time required to assign a triage category to each simulated patient, measured automatically from first patient contact to final triage decision within the simulation platform. Results will be analyzed as mean triage time per patient and/or per participant.	Through study completion, an average of 1 hour
Overtriage rate	Proportion of patients assigned to a higher priority category than clinically indicated according to the reference standard (HUMAn simulation model). Expressed as a percentage of total triage decisions per participant.	Through study completion, an average of 1 hour
Undertriage rate	Proportion of patients assigned to a lower priority category than clinically indicated according to the reference standard. Expressed as a percentage of total triage decisions per participant.	Through study completion, an average of 1 hour
User satisfaction and perceived ease of use	Participant-reported evaluation of the assigned triage algorithm, measured using a post-simulation questionnaire (e.g., Likert-scale items assessing clarity, ease of application, and overall satisfaction on a scale of 1 "Very unsatisfied/Not clear at all/Very difficult to apply to 5 "Very satisfied/Absolutely clear/Very easy to apply).	Through study completion, an average of 1 hour

Collaborators and Investigators

• Sponsor: Stuby Loric
• Collaborators: University Hospital, Geneva; HEIG-VD- Haute Ecole d'Ingénierie et de Gestion du Canton de Vaud; École Supérieure de Soins Ambulanciers - College of Higher Education in Prehospital Care
• Investigators: Principal Investigator: Loric Stuby, Genève TEAM Ambulances

Study record dates

Study Major Dates

• Study Start (Actual): February 13, 2026
• Primary Completion (Actual): March 13, 2026
• Study Completion (Actual): March 13, 2026

Study Registration Dates

• First Submitted: February 13, 2026
• First Submitted That Met QC Criteria: February 20, 2026
• First Posted (Actual): February 27, 2026

Study Record Updates

• Last Update Posted (Actual): April 22, 2026
• Last Update Submitted That Met QC Criteria: April 17, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Randomized controlled trial; Emergency Medical Services; Triage; Simulation; Mass casualty incident; Prehospital Triage; Simulation training; Disaster medicine; Emergency medical services (EMS); Triage accuracy; Ten Second Triage (TST); Overtriage and undertriage; Blunt and penetrating trauma; Sieve; Simulation-based; Major incident preparedness; Triage algorithms
• Other Study ID Numbers: Sieve vs TST

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The dataset will likely be shared in an open repository, but this still needs to be discussed with the entire study team.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No