Differential diagnosis compiles potential causes, then eliminates them based on clinical evidence until the most probable remains. In litigation the process is often termed differential etiology because it addresses cause rather than diagnosis.
Courts generally accept it as a reliable methodology when properly performed.
Alternative Names:
Differential Etiology, Ruling In and Ruling Out
Why it Matters?
Admissibility turns on whether the expert actually performed both steps. Ruling in requires evidence that the proposed cause is capable of producing the condition, which depends on general causation. Ruling out requires addressing plausible alternatives rather than dismissing them summarily. An expert who ruled in the defendant's product without general causation support, or who failed to address obvious alternatives such as smoking or idiopathic occurrence, is vulnerable.
Frequently Confused with
Related terms
Frequently asked questions
What are the two steps of differential diagnosis?
What is the most common basis for exclusion?
