(concurring). I concur in the judgment of the court. I agree that the trial judge erred in denying the defendant doctor’s motions for a directed verdict and for judgment notwithstanding the verdict. However, I reach this conclusion on the basis that the evidence was legally insufficient on the question of causation. I do not agree with the court that the evidence was legally insufficient on the question of the defendant doctor’s duty to disclose and his failure to perform that duty. In my view, the court’s discussion of a physician’s duty to inform a patient of the material risks inherent in a course of treatment emasculates the rule enunciated in Harnish v. Children’s Hosp. *698Medical Center, 387 Mass. 152, 155 (1982). This treatment by the court is not only erroneous on the facts of the case, but also unnecessary. Hence, I write to state my views.
We held in Harnish v. Children’s Hosp. Medical Center, supra, that “a physician owes to his patient the duty to disclose in a reasonable manner all significant medical information that the physician possesses or reasonably should possess that is material to an intelligent decision by the patient whether to undergo a proposed procedure.” We defined “materiality” as “the significance a reasonable person, in what the physician knows or should know is [the] patient’s position, would attach to the disclosed risk or risks in deciding whether to submit or not to submit to surgery or treatment.” Id. at 156, quoting Wilkinson v. Vesey, 110 R.I. 606, 627 (1972). We said further that material information “may include ... the nature and probability of risks involved” in a procedure, but that “[t]he obligation to give adequate information does not require the disclosure of all risks of a proposed therapy. ” Harnish, supra.
Today the court states the straightforward proposition that “[t]he materiality of information about a potential injury is a function not only of the severity of the injury, but also of the likelihood that it will occur.” Ante at 694. See Canterbury v. Spence, 464 F.2d 772,788 (D.C. Cir.), cert. denied, 409 U.S. 1064 (1972) (“The factors contributing significance to the dangerousness of a medical technique are . . . the incidence of injury and the degree of the harm threatened”); LaCaze v. Collier, 434 So. 2d 1039, 1046 (La. 1983) (“Materiality is, in essence, the product of the risk and its chance of occurring”); Wilkinson v. Vesey, supra at 627-628 (“Among the factors which point to the dangerousness of a medical technique are the severity of the risk and the likelihood of its occurrence”); Smith v. Shannon, 100 Wash. 2d 26, 33 (1983) (“The determination of materiality is a 2-step process. Initially, the scientific nature of the risk must be ascertained, i.e., the nature of the harm which may result and the probability of its occurrence”).
In the present case, the plaintiffs argue that the information that Precourt’s eye surgery would necessitate a prolonged course of treatment with Prednisone, and that the administration *699of Prednisone would present a risk that he would develop the condition known as aseptic necrosis, which involves irreversible bone death, was material information which the defendant had a duty to disclose. The court, without foundation ih fact or law, holds that the plaintiffs failed to prove that this information was material: “[T]here was no evidence of the likelihood that a person would develop aseptic necrosis after taking Prednisone or that Frederick knew or should have known that the likelihood was other than negligible.” Ante at 696.1 disagree. The record reveals ample evidence of the severity of the harm involved in the condition of aseptic necrosis and the probability that Precourt would develop this harmful condition.
Initially, I note that, in reviewing the trial court’s denial of a motion for a directed verdict and for judgment notwithstanding the verdict, this court must “examine the evidence in the light most favorable to the plaintiff.” Forlano v. Hughes, 393 Mass. 502, 504 (1984). In so viewing the evidence in the record, the court’s task is to determine “whether ‘anywhere in the evidence, from whatever source derived, any combination of circumstances could be found from which a reasonable inference could be drawn in favor of the plaintiff. ’ Poirier v. Plymouth, 374 Mass. 206, 212 (1978).” Forlano v. Hughes, supra, quoting Miles v. Edward O. Tabor, M.D., Inc., 387 Mass. 783, 786 (1982).
Dr. Frederick does not dispute that aseptic necrosis is a very severe condition. He himself defined aseptic necrosis as “the cell death of a [portion] of the joint.” He agreed that aseptic necrosis is a debilitating and irreversible condition involving bone death and distribution of the bone tissue. The evidence warrants the conclusion that Precourt suffered this condition as a result of the prescribed use of Prednisone.1 As a result, Precourt has a condition which necessitates total replacement of both the right and left hips. The evidence shows also that, even with successful hip replacement surgery, Precourt under*700went a significant life-style change. Before he developed aseptic necrosis, he had worked as a licensed electrician. At the time of the trial, having undergone a successful replacement of one hip and awaiting replacement of the other, he worked as a store clerk. He was unable to lift or carry heavy items, to climb, or to walk long distances. He walked with a cane and was unable to sit or stand for long periods.
The record contains sufficient evidence that Precourt could develop aseptic necrosis as a result of his treatment with Prednisone and that Dr. Frederick knew, or reasonably should have known, of this risk to Precourt. Dr. Frederick testified that he knew, from reading, attending conferences, and engaging in discussions with his colleagues, that the use of Prednisone has been associated with the condition of aseptic necrosis. Dr. Frederick characterized aseptic necrosis as one of “the most prominent” musculoskeletal side effects of Prednisone. Dr. Melvin W. Kramer, one of the plaintiff’s expert witnesses, a physician board-certified in internal medicine, testified that the side effects of Prednisone “are made known to every physician who obtains a diploma from medical school.” Dr. Kramer also testified that Precourt received a “high dose” of Prednisone over a “long course of therapy.” Dr. Joseph Bowlds, an ophthalmologist who testified as an expert witness for the defendant, stated that “[t]he greater the exposure to [Prednisone], the greater the frequency of the complications.”
The evidence that aseptic necrosis was a well documented, generally known, and very serious side effect of Prednisone; that the risk of aseptic necrosis increases with extended exposure to Prednisone; and that Precourt was prescribed by Dr. Frederick a “high dose, long course of therapy” with Prednisone is sufficient to meet the plaintiffs’ burden regarding materiality. Many courts have stated that, while “materiality” is a function of severity and likelihood, the more severe the harm, the less likely the harm need be for information concerning the risk to be considered material by the fact finder. “A very small chance of death or serious disablement may well be significant; a potential disability which dramatically outweighs the potential benefit of the therapy or the detriments of the existing malady *701may summons discussion with the patient.” Canterbury v. Spence, supra. Wilkinson v. Vesey, supra at 628 (same). McKinney v. Nash, 120 Cal. App. 3d 428, 441 (1981) (“The low incidence of testicular atrophy weighs against materiality. The seriousness of testicular atrophy is debatable as well. Yet we cannot say, as a matter of law, that a jury reasonably could find that knowledge of this risk was not material to plaintiff’s decision”). Cf. LaCaze v. Collier, 434 So. 2d 1039,1046 (La. 1983) (“A severe consequence, ordinarily of interest to the patient, would not require disclosure if the chance of the consequence occurring was so remote as to be negligible”).
While I believe that the evidence described above is sufficient for a fact finder to conclude that the information was material, there was additional evidence that Precourt could develop aseptic necrosis, which puts it beyond dispute that there was sufficient evidence to submit the materiality question to the jury. Precourt’s medical history indicated that he was a “high risk” for aseptic necrosis. Dr. Kramer testified that he had reviewed Precourt’s records from the Massachusetts Eye and Ear Infirmary and that the records revealed that “[o]n both occasions [both operations], the medical consultation prior to operation recorded the alcohol consumption of six beers per day.” As the court describes, ante at 694, Dr. Kramer also testified that “ ‘ [t]he combination of sustained steroid therapy in a cumulative fashion adding up to many weeks, many months of therapy, has the ability to alter body chemistry in a known and critical fashion. And patients who have associated medical conditions, such as alcohol consumption, or other such metabolic conditions, the patient then becomes a high risk for the development of certain particular disorders. One of these disorders is aseptic necrosis of the bone or hip.’ ” (Emphasis added.)2
*702It is clear to me that there was sufficient evidence of both the severity of the harm and the likelihood that the harm would occur for the question of materiality to go to the jury. Moreover, while the issue whether risk information is material encompasses the questions of the severity of the harm and the likelihood of its occurrence, the issue is significantly broader. It is “the significance a reasonable person, in what the physician knows or should know is [the] patient’s position, would attach to the disclosed risk or risks” (emphasis added). Harnish v. Children’s Hosp. Medical Center, 387 Mass. 152,156(1982), quoting Wilkinson v. Vesey, supra at 627. The very basis of the materiality standard is the patient’s need. See generally Canterbury v. Spence, 464 F.2d 772, 786-788 (D.C. Cir. 1972). “[T]he patient’s right of self-decision shapes the boundaries of the duty to reveal.” Id. at 786. While measured by an objective standard of a reasonable person in the plaintiff’s position, the question whether information is material to a patient is substantially an individual decision. In a case such as the present one, in which it is the patient’s own particular medical history which leads an expert witness to testify that Precourt was a high risk for a serious and debilitating condition, it is beyond peradventure that the question should go to the jury. Id. at 788 (“Whenever non-disclosure of particular risk information is open to debate by reasonable-minded [persons], the issue is for the finder of the facts”).
While I have written separately because I believe that the evidence on the materiality question was sufficient to go to the jury, I concur in the judgment of the court that the trial judge erred in denying the defendant’s motions for a directed verdict and for judgment notwithstanding the verdict. The evidence was legally insufficient on the question of causation. “At trial, the plaintiff must also show that had the proper information been provided neither he nor a reasonable person in similar circumstances would have undergone the procedure.” Harnish v. Children’s Hosp. Medical Center, supra at 158. *703Canterbury v. Spence, supra at 790-791. Precourt testified that, even if Dr. Frederick had informed him of the risk that he would develop aseptic necrosis, he would have undergone the first operation. He testified, however, that he would not have undergone the second operation. There was insufficient evidence that Precourt’s condition was caused by the drug therapy administered after the second operation. Dr. Kramer testified that Precourt’s condition was caused by the cumulative effect of the drug. He did not testify that it was more probable than not that Precourt’s condition was caused by the drug therapy administered after the second operation.3 The plaintiffs presented no other evidence to establish that the course of therapy after the second operation was more probably than not the cause of Precourt’s aseptic necrosis. The evidence on the causation question was insufficient to warrant submission of the case to the jury. See Forlano v. Hughes, 393 Mass. 502, 507-508 (1984), and cases cited.
In his brief to this court, Dr. Frederick concedes that the jury would be warranted in finding that Precourt’s Prednisone therapy caused him to develop the condition of aseptic necrosis.
The court dismisses this evidence with the statement that “‘[h]igh’ is a relative word. It could mean one in ten, but it could just as well mean one in a million.” Ante at 696. I do not understand the court’s.facile dismissal of this important testimony of an expert witness. “High” is indeed a relative term, and this expert in effect testified that Precourt was a high risk, relative to other persons, for the development of aseptic necrosis. I think this is just the type of evidence contemplated by those courts that have called for expert testimony on “the nature of the harm which may result and the prob*702ability of its occurrence.” Smith v. Shannon, 100 Wash. 2d 26, 33 (1983). See Winkjer v. Herr, 277 N.W.2d 579, 588 (N.D. 1979).
On cross-examination, Dr. Kramer was asked, “You cannot say that had [Precourt] not taken the course [of therapy after the second operation], he wouldn’t have come down with aseptic necrosis, can you?” Dr. Kramer answered, “No, sir.”