Triage Engine

The Health Navigator Triage Engine calculates a triage score and a level of care recommendation (disposition) for use in consumer health bots and triage symptom checker applications. Based on user-entered symptoms, the Triage Engine provides answers to consumer questions such as: “do I need to see a doctor?“, “how serious might this be?“, “when and where should I go for care?” Factors that are considered include the chief complaint(s), age, gender, symptom severity and duration, known medical problems, and other clinical findings.

The Health Navigator Triage Engine is a knowledge-based decision support tool. It uses a proprietary multi-factor decision tree algorithm to make a triage level of care recommendation, using as inputs: age, gender, pregnancy status, symptoms, known medical problems, and other clinical factors. This expert system is a structured and evolving database of curated content from subject matter expert input, literature review, data mining and analytics, and testing against large clinical data sets. It reflects triage knowledge and expertise from over two decades of work with emergency departments and medical call centers.

Here is an example use case scenario. This example illustrates how the triage engine might be used in a health bot or digital health assistant:

John Gomez is 24 years old, male, and has no ongoing medical problems. He started having crampy stomach pain about 6 hours ago. The pain has become constant, is now severe, and seems to be mostly in his right lower abdomen area. He has no back pain, fever, or diarrhea. He has not vomited, but does feel sick to his stomach and has lost his appetite.

John is worried that this might be appendicitis. He is most interested in knowing if he should see a doctor and when should he go. John enters his symptoms into the health bot on his mobile phone. The health bot recommends that he go to the emergency department for evaluation right away.


Triage Health Bot


How it works…


The Health Navigator Triage Engine is provided for use by our partners through an easy to implement application programming interface (API).

The graphic below shows a high-level workflow of a consumer diagnosis symptom checker or health bot.


Triage Engine - High Level Work Flow


  1. What’s Wrong? The first step is find out what is the user’s main symptom or problem. The main symptom or problem is also called the chief complaint. This is best done using the Health Navigator Natural Language Processing (NLP) engine. For example, the user might enter “My stomach hurts. No appetite.” A single call to the FindCCCbyPopulation method and the NLP technology converts this free-text into acuity-coded chief complaints (Abdomen Pain, Anorexia – Loss of Appetite). These clinical concepts and their associated concept IDs are used as data in the remainder of the process.
  2. Tell Us More. The second step is to ask the user to “tell us more” about their primary and secondary complaint(s). This is easily achieved by calling three Clinical Documentation Support (CDS) methods using the clinical concept IDs from the first step:
    • TellUsMorePrimaryCCC
    • TellUsMorePrimaryCCC_OPQRST
    • TellUsMoreSecondaryCCC_OPQRST_Severity
  3. Calculate Triage Score. The third and final step is to calculate a triage score. This is accomplished by a single call to the Triage Engine method CalculateTriageScore. The input parameters for the CalculateTriageScore method include: primary chief complaint (concept ID), age, gender, pregnancy status, LanguageID, and all other clinical findings (concept ID; present or absent).

The Triage Engine is available in eight languages. The Triage Engine can be used along with the Diagnosis Engine to develop a combined triage and diagnosis symptom checker app or health bot.


How it improves care…


With the Health Navigator Triage Engine you can build digital health assistants that can help your patients get the right care, at the right place, at the right time.

Here is how a triage health bot or symptom checker can improve patient care:

  • Empower and educate patients to make better decisions regarding when and where to seek healthcare
  • Improve patient safety
  • Capture patient responses as clinical data (Concept ID, SNOMED) and pass it into the electronic health record as an eVisit check-in process
  • Redirect patients to telemedicine or a nurse advice line (medical call center)
  • Reduce unneeded emergency department visits
  • Provide helpful care advice


A multi-channel approach…


Using Health Navigator’s clinical content and APIs, your organization can build applications across multiple channels. Here is one last use case scenario. This scenario illustrates how the triage engine might be used in a consumer-facing browser-based triage symptom checker:

Adrien Girard is 21 years old, male, lives in London, and just returned from travel to Africa. He has had increasing and watery diarrhea (diarrhoea) for the last 3 days. He has mild stomach pain that comes and goes. He has had no fever and there is no blood in his stool. He has no ongoing medical problems.

Adrien wants to know if he should see a doctor and when should he go. Adrien enters his symptoms into the symptom checker application on his laptop computer. The symptom checker recommends that he call or see a healthcare provider today or tomorrow. It also gives him easy-to-use self care advice for treating diarrhea.


Triage Engine - Diarrhea - What is Wrong

Triage Engine - Diarrhea - Tell Us More

Triage Engine - Care Advice for Diarrhea