(Please note: the names and locations of all parties have been changed to protect the confidentiality of the proceedings.)
II MEDICAL OPINION TESTIMONY MUST BE TO A REASONABLE MEDICAL PROBABILITY
An expert witness – including a medical doctor – must testify on issues of the standard of care, causation and damages, in the field of his expertise, to a reasonable medical probability. Clearly, “[a]bsolute proof or mathematical demonstration is not required.” (Foremost Dairies v. Industrial Acc. Com. (1965) 237 Cal. App.2d 560, 568-569, citing Santa v. Industrial Ace. Com. (1917) 175 Cal. 235, 237.) However, an expert must testify to a reasonable medical probability as opposed to offering mere guess work, speculation, conjecture or bare possibilities.
Conversely, if the expert cannot testify as to a reasonable medical probability as to one of the elements of medical negligence – standard of care, causation, or damage – such testimony cannot be admitted. This fundamental principle that an expert must testify to a reasonable medical probability was stated in Rowley v. Bunnell (1968) 257 Cal. App.2d 324, where establishing the time of death of two testators was at issue:
“Medical witnesses need not testify positively to support a finding of proximate cause. Their opinion of-the probabilities is sufficient for that purpose.” (Emphasis added.) (Rowley, supra, 257 Cal.App.2d at p. 341.) See also Tannyhill v. Pacific Motor Transportation Company (1964) 22 Cal. App.2d 511,521, citing to Travelers Insurance Company v. Industrial Ace. Corn. 22 Cal.2d 685. (See Robertson v. Leigh (1957) 153 Cal. App.2d 730.)
In Collum v. Seifer (1969) 1 Cal.App.3d 20, a medical malpractice action, the jury found for the defendant, but the court granted plaintiffs motion for a new trial. The Second Appellate District affirmed on the basis that expert testimony supported the inference that to a reasonable medical probability, plaintiff would have benefited by prompt diagnosis and treatment of her cancer. In other words, the expert testimony must show that the treatment within a reasonable medical probability would have had an effect on the plaintiff. “It is often impossible to show by positive proof whether or not an impairment of health or faculties will follow as a result of injury. Hence, of necessity, in determining the question courts and juries must rely upon the testimony of properly qualified physicians for such testimony as will, in the minds of the jury, establish the fact in issue to a reasonable certainty. Such evidence must be clearly distinguishable from conjecture, or that which merely establishes a possibility of future trouble.” (Emphasis added.) (Collum v. Seifer, supra, 1 Cal. App.3d at p. 26.)
In Santa v. Industrial Acc. Corn., supra, 175 Cal. 235, 237, judgment for the defendant was affirmed because the court found that the expert pathologist gave “what, on the facts before him, and in the light of medical science, appeared to be the most probable explanation of the event” (emphasis added) in his testimony regarding the connection between plaintiffs and the defendant’s action. (See Part 3 of 3.)
For more information you are welcome to contact Sacramento personal injury lawyer, Moseley Collins.