Differential Diagnosis Applied to the Decision-Making Process
“We have the only cookbook in the world that has partial differential equations in it.”
Nathan Myhrvold
In medicine, differential diagnosis (sometimes abbreviated DDx, ddx, or ΔΔ) is the systematic method healthcare providers use to identify the disease causing a patient's symptoms. A skilled diagnostician will use probabilistic reasoning when deciding which ailment is the most likely.
“When you hear hoofbeats look for horses not zebras.”
Dr. Theodore Woodward
According to Scott D.C. Stern, Adam S. Cifu, Diane Altkorn
Differential diagnosis allows the physician to:
1. More clearly understand the condition or circumstance
2. Assess reasonable prognosis
3. Plan treatment or intervention for the condition or circumstance
4. Enable the patient and the family to integrate the condition or circumstance into their lives, until the condition or circumstance may be improved, if possible.
Differential Diagnosis Framework
• Collect Data
• Distill the Data into Pertinent Positive and Negative Findings.
• Create a problem representation-- define the problem representation as “an abstract one-sentence summary of the key features of the case synthesized in the clinician’s mind.”
• Adopt a Differential Diagnosis Framework
• Apply the Pertinent Positive and Negative Findings to the Framework
Here are 10 tips that will help improve your differential diagnostic skills.
1. You won’t find what you don’t consider.
2. Cast a wide net of possibilities, but avoid zebras.
3. The differential diagnostic process consists of considering the possibilities and narrowing them down to probabilities.
4. All levels of in the process should use the differential diagnostic process at some level.
5. A “SAMPLE” history is a mnemonic used in the medical field:
S- Signs/Symptoms
A- Allergies
M- Medications
P- Pertinent Medical History
L- Last Oral Intake
E- Events leading up to illness/injury
In business P is important in determining possibilities and probabilities but E is important in determining the events leading up to the issue.
6. Although we can’t do lab tests and CT scans, it’s amazing what a thorough asking of the right questions can tell us.
7. Always treat life threats before you begin the differential diagnostic process.
8. If best history question doesn’t give you an answer—it gives you two more questions to ask.
9. Patients lie.
10.Just because a patient doesn’t have a history of a particular condition doesn’t mean it can’t happen. Every disease has a first occurrence.
Additional Reading
Critical Thinking in Business: Revised and Expanded Second Edition by Bob Schoenberg
The Decision Book: Fifty Models for Strategic Thinking by Roman Tschäppeler, Mikael Krogerus & Jenny Piening
Point of Reflection
“Teach your tongue to say “I do not know” and you will progress.”
Rabbi Moses Ben Maimon Maimonides