I get questions all of the time on various workers' compensation topics, but probably one of the most common subjects concerns evidence, or more specifically, what kind of evidence do workers' compensation judges rely upon.
The simple answer is that in most jurisdictions the evidentiary standard is "substantial evidence."
I know this doesn't help because the term, "substantial evidence," is one of those esoteric legal concepts that has no meaning outside the context of factual application.
Case law has defined "substantial evidence" as what a reasonable mind might accept as adequate to support a conclusion.
Yeah - that's clear as mud!
Who's reasonable? And "might accept"? What about "might NOT accept"? And "adequate" - oh boy.
Forget those legal scholars and these lame attempts to define the undefinable - bottom line is that "substantial evidence" is just, "good enough."
If you have something that you want to support, the evidence just has to be "good enough" to justify whatever conclusion you are trying to derive from it. It doesn't matter that there are five other reports stating the opposite, or that there are more pages, or better author reputations - though those factors may weigh on the value of the evidence.
This is why, in workers' compensation, medical reports that seem kind of shady are "good enough" to support an award. If the judge wants to get to a conclusion and the evidence is "good enough" to get the judge there, then it is "substantial evidence" even if there is other evidence that may be better.
And there does not have to be any certain quantity of evidence to make anything "substantial." One report that has a conclusion different than a half dozen other reports can still be "substantial evidence" so long as it is reasonable to draw the conclusion for which it is proffered.
This doesn't mean that just any evidence can be "substantial" to support an award. Many states have rules and regulations that define what the medical evidence shall contain and the topics covered. Because these regulations are mandatory in nature, failure of a medical report to meet these minimum standards means that such report can not be "substantial evidence."
For example, a regulation may require certain disclosures, or a declaration under penalty of perjury. The failure to meet these minimum standards would make the report incomplete and as a consequence not "substantial" for purposes of evidence because a reasonable mind can not rely upon the report - the author failed to meet mandatory requirements dictated by law.
But the single biggest failure in medical reporting is an error in history - either the history of the injury or the relevant medical history of the claimant.
The error in history needs to be significant enough that some other conclusion would be inevitable if the error did not exist. For instance, if there were facts that would implicate some other cause of injury, or some pre-existing condition, that were not accounted for by the report, which if were considered would lead to a different conclusion - that would not be "substantial evidence."
Another way for a medical report to fail to meet the substantial evidence standard would be if the author were relying on an incorrect legal theory. An example would be if the author were relying upon standards that existed prior to a change in the law - e.g. the threshold of psychological injury in California.
And the report must be based on a reasonable medical probability, not just possibility. Which is to say speculation can not be substantial evidence.
There are of course many more intricacies of this esoterica, because this is one of those legal things that drives engineers and other digit-minded brains nuts; the notion of "substantial evidence" is vague and soft around the edges. There is no clearly defined boundary.
US Supreme Court justice Potter Stewart drew fame in his short concurrence in the pornography case, Jacobellis v. Ohio (1964) with the phrase, "I know it when I see it." That's the standard of substantial evidence.