What does the software do?
The fundamental tasks performed by the DDSS are as follows:
- Computes differential diagnosis – the ranked list of candidate diseases a patient might have based on the findings (symptoms, signs and test results) you enter.
- Suggests useful findings based on the evolving differential diagnosis.
- Provides contextual links to other resources, including articles, images, etc.
- Reveals the logic so you can assess if you believe it. Compares the entered findings to those in the selected disease.
Where do I start?
You must enter the age and sex of the patient to get started. These get entered on the Start screen. Then you can add your first finding, by going to search and typing the finding into the green search box. Next to each finding is a pull-down menu with a “?”. This is where you specify onset or absence, and add the finding to the patient’s phenotype.
Does it matter which finding I add first?
To maximize efficiency, start with the most unusual finding. A set of findings will produce the same differential diagnosis regardless of the order in which they are entered. However, the useful findings suggested and the differential diagnosis will differ before the full set of findings is entered.
Why does the software focus on the time-course of findings?
The database has the time course of each finding in each disease. By specifying the time course in your patient, you get a better differential diagnosis.
Why specify pertinent negatives?
Diagnoses of exclusion and pertinent negatives are a critical part of diagnosis.
Where do findings “go” once I add them?
The findings you have added are collected on the Phenotype tab under Dx on the top black navigation bar.
How do I erase a finding I previously added?
Go to Dx/Phenotype and under the presence button, click “Not specified”.
How do I enter test results?
Go to Dx/”Add tests” for suggestions of useful tests or use search under the magnifying glass. For some problems and specialties there are collections of key tests in the workups (W/u on the top black navigation bar).
Where do I enter Family history?
On the Initial screen, click the Transmission button to get the popup to specify if others in the family are affected, if known. On many other screens a finding “Transmission history” will appear and you can comment by clicking the component to the left of that finding.
If common diseases have already been ruled out, how do I reduce the common diseases in the differential diagnosis?
On the initial screen, specifying Primary, secondary or tertiary allows you to adjust for the incidence of the disease, and is useful for when a patient has already had many conditions ruled out or where the disease may be newly described and the incidence not well known.
What do I do if I want to read more about a finding or disease?
Click the button of the name of the finding or the disease and then click 🔗 on the top black navigation bar to go to related resources about the finding or disease.
How do I check synonyms of a finding or disease?
Hover over the name of the finding or diseases to see synonyms.
Does the software use machine-learning?
No, the software does not use machine learning-based artificial intelligence. The database is built through manual curation by expert clinicians. Machine learning is not good at unlearning information no longer believed to be true, and it is not good at using the frequency of findings in diseases to enable the use of pertinent negative findings in diagnosis.
What do the colors mean?
- Blue is used for diseases
- Green is used for findings
- The current age period is black. Later is purple. Earlier is brown.
What is the difference between “usefulness” and “pertinence”?
The two concepts are related.
- Usefulness is prospective, a computational statistical metric of how much additional information would change the differential diagnosis.
- Pertinence is retrospective, a computational statistical metric of how much this finding has driven the differential diagnosis.
What file format can the software read to load the patient?
You can load a URL that the software outputs with the patient’s findings or the Patient Summary PDF output from the software.
How do I update my name and title that appears in the Patient Summary?
From any page on the SimulConsult Web site other than the page running the software, hover over the My Account menu, then choose “Account details”.
Is there a “rule out” feature?
Yes. Once you select a disease as active by clicking on it, two options will appear in the the Add findings tab and Add tests tab: “Usefulness in all diseases” and “Rule in or out selected disease“.
What is the difference between the Profile of the Finding and of a Disease?
- The Profile of a Finding is diseases with the finding.
- The Profile of a Disease is findings in that disease.
How do I find the app in the app store?
There is no need to install an app to run on mobile platforms. The diagnostic tool runs from the same URL as it does on personal computers.
How is the dominant versus recessive character of an X-linked disease handled?
In simpler times, it was common to refer to an X-linked disease as dominant or recessive. Now, it is recognized that many X-linked diseases have a mixture of the two types of expression. A good example is X-linked adrenoleukodystrophy, where the leukodystrophy is dominant and the adrenal deficiency is recessive (losing half of myelin cells is enough to block axonal transmission but losing half of hormone-producing cells is less problematic).
The diagnostic software applies both recessive and dominant models to X-linked diseases, according to the recessive versus dominant character of the disease. For some diseases, there are separate listings for forms of the disease in males and females.
Can the software be used in prenatal settings?
SimulConsult has lots of material on prenatal findings, curated from many sources, including the Woodward “Diagnostic Imaging: Obstetrics” and Benacerraf “Ultrasound of Fetal Syndromes” textbooks. See prenatal use