Milliun v. New Milford Hospital

****************************************************** The ‘‘officially released’’ date that appears near the beginning of each opinion is the date the opinion will be published in the Connecticut Law Journal or the date it was released as a slip opinion. The operative date for the beginning of all time periods for filing postopinion motions and petitions for certification is the ‘‘officially released’’ date appearing in the opinion. In no event will any such motions be accepted before the ‘‘officially released’’ date. All opinions are subject to modification and technical correction prior to official publication in the Connecti- cut Reports and Connecticut Appellate Reports. In the event of discrepancies between the electronic version of an opinion and the print version appearing in the Connecticut Law Journal and subsequently in the Con- necticut Reports or Connecticut Appellate Reports, the latest print version is to be considered authoritative. The syllabus and procedural history accompanying the opinion as it appears on the Commission on Official Legal Publications Electronic Bulletin Board Service and in the Connecticut Law Journal and bound volumes of official reports are copyrighted by the Secretary of the State, State of Connecticut, and may not be repro- duced and distributed without the express written per- mission of the Commission on Official Legal Publications, Judicial Branch, State of Connecticut. ******************************************************  LESLIE MILLIUN v. NEW MILFORD HOSPITAL ET AL. (SC 18845) Rogers, C. J., and Norcott, Zarella, Eveleigh and McDonald, Js.* Argued September 27—officially released December 31, 2013  Michael G. Rigg, for the appellant (named defendant). David S. Golub, with whom were Jonathan M. Levine and, on the brief, Marilyn J. Ramos, for the appellee (substitute plaintiff).  Opinion McDONALD, J. In the present case, we principally examine the circumstances under which a treating phy- sician’s medical records can be admitted as expert evi- dence of causation in a medical malpractice action. The trial court rendered summary judgment in favor of the defendant New Milford Hospital1 on the ground that the plaintiff, Lynnia Milliun, the conservator of her sister, Leslie Milliun (Leslie),2 had failed to offer the requisite expert testimony to create an issue of material fact regarding the defendant’s alleged negligence as the proximate cause of Leslie’s injuries. The Appellate Court reversed that judgment, rejecting the trial court’s conclusions that: (1) certain medical records of Leslie’s treating physicians were inadmissible as expert opinion on causation because statements in the reports on that matter were both hearsay and made by lay witnesses; and (2) its order granting the plaintiff’s motion for the appointment of a commission so that Leslie’s out-of- state treating physicians could be deposed should be withdrawn because the physicians could not be com- pelled to offer expert opinion on causation. Milliun v. New Milford Hospital, 129 Conn. App. 81, 20 A.3d 36 (2011). Upon our grant of certification, the defendant appeals from the Appellate Court’s judgment challeng- ing both of these determinations. We affirm the judg- ment of the Appellate Court. The Appellate Court’s opinion sets forth the following undisputed factual and procedural history. ‘‘Prior to [July, 2002, Leslie] had been a patient in the defendant’s care in connection with the treatment of her stiff man syndrome (SMS) [a rare, disabling neurological disorder characterized by progressive, severe muscle stiffness or rigidity as well as painful muscle spasms triggered by sensory stimuli.3 From July 9, 2002 to July 14, 2002, Leslie was admitted to the defendant for treatment relat- ing to that condition.] In her amended complaint, the plaintiff alleged that, while in the defendant’s care, Les- lie suffered severe respiratory dysfunction, during which time her rate of breathing was reduced to two breaths per minute for a period of four minutes. As a result of this anoxic4 incident, the plaintiff further alleged, Leslie had suffered severe injury to her cogni- tive functioning, including memory loss, loss of motor function and speech impairment. The plaintiff claimed that Leslie’s brain injury was caused by the defendant’s negligence, namely, failure to monitor Leslie properly, failure to respond to her respiratory dysfunction and the administration of medication that is known to cause respiratory dysfunction [when combined with other medications such as Valium]. ‘‘In April, 2003, prior to the commencement of this action, Leslie had sought treatment at the Mayo Clinic in Rochester, Minnesota, [seeking a second opinion regarding her diagnosis of SMS and expressing con- cerns about, inter alia, diminished cognitive function since the previous July]. At the Mayo Clinic, she first was seen by Kathleen M. McEvoy, a physician. McEvoy reported that Leslie had brought extensive outside records with her, along with an investigative report from the department of health [state board] regarding the anoxic incident that occurred while she was in the care of the defendant. McEvoy’s admittance notes indicated that the plaintiff also reported this event to her. At that time, McEvoy reported in her evaluation that Leslie was suffering from a severe neurological disorder, and, although some manifestations suggested SMS, ‘she obviously has additional deficits and involve- ment that would not be expected with [SMS] alone.’ ‘‘In February, 2005, Leslie returned to the Mayo Clinic to address [concerns about her SMS and diminished cognitive functioning following the July, 2002 hospital- ization]. In her evaluation report, McEvoy stated her impressions of Leslie’s condition as follows: ‘It is still my clinical impression based on the temporal profile of the onset of her symptoms, that [Leslie] has a primary autoimmune disorder consistent with [SMS], which by history was associated with dysarthria5 but no cognitive impairment, along with a superimposed anoxic enceph- alopathy6 which developed by her report of July 10, 2002 . . . .’ ‘‘McEvoy then referred Leslie to physicians Keith A. Josephs and Stefan A. Dupont at the Mayo Clinic’s behavioral neurology unit for the purpose of assessing her cognitive functions. Upon his neurological examina- tion, Dupont, a resident at the Mayo Clinic [under Josephs’ supervision], reported in his neurology consult that her ‘cognitive dysfunction appears to be multido- main in nature, and based on the recounted temporal events, this all seems to have occurred because of anoxic encephalopathy suffered during her respiratory arrest in 2002.’ ‘‘Josephs’ evaluation echoed Dupont’s conclusion. He reported as follows: ‘It is my opinion that [Leslie’s] cognitive impairment is secondary to whatever event occurred or whatever transpired in 2002. The family member tells me that there was anoxia and that there was a change after that. Therefore, one must conclude that her cognitive impairment was secondary to the event that occurred in 2002. Arguing for this being the process of her cognitive impairment also is the fact that she has not had any significant progression since 2002. The cognitive impairment in my opinion is not related to the patient’s diagnosis [of SMS] and is not in keeping with a neurodegenerative syndrome given the lack of progression.’ Josephs went on to diagnose her as suffer- ing from ‘cognitive impairment (static encephalopathy secondary to anoxic brain damage).’ ‘‘In July, 2008, the plaintiff filed the underlying amended complaint in which she alleged that the defen- dant was negligent in its care and treatment of Leslie. The court scheduled trial to commence on January 21, 2009, and the plaintiff was required to disclose all of her expert witnesses by September 15, 2008. On that date, the plaintiff disclosed nine expert witnesses, [five of whom were Mayo Clinic physicians or neuropsychol- ogists] including McEvoy and Josephs. All [of the Mayo Clinic providers] were identically disclosed on the issues of causation and damages. ‘‘In November, 2008, the defendant filed a motion to preclude the plaintiff from calling any of her expert witnesses at trial, contending that she had failed to make them available for depositions and, therefore, that it would be prejudiced by having to conduct pretrial discovery so close to the forthcoming trial date. At a subsequent hearing before the court on the motion to preclude, counsel for both parties indicated that they were experiencing difficulty deposing the plaintiff’s experts, as the Mayo Clinic had an internal policy that limited the depositions of its treating physicians. In response to the court’s concerns, the plaintiff repre- sented that none of the witnesses from the Mayo Clinic had been retained as experts to be called at trial but instead had been disclosed as experts for the purpose of introducing their medical records. At the conclusion of the hearing, the parties agreed to take the depositions by teleconference, limited to questions concerning the information contained in the treating physicians’ medi- cal reports. ‘‘On January 26, 2009, the court held a hearing on the status of the depositions. At the hearing, the defendant again expressed concern over not having had the oppor- tunity to depose all of the plaintiff’s experts. The court thereafter stressed to the parties that the defendant had the right to obtain the deposition testimony of any treating physicians on whose medical reports the plain- tiff intended to rely at trial. The plaintiff then explained that, because the witnesses were not within her control, the most appropriate action would be to have a commis- sion appointed in order to compel the experts to attend their depositions in Minnesota in accordance with Gen- eral Statutes § 52-148c.7 The following day, the plaintiff filed a motion for the appointment of a commission to summon by subpoena and to obtain the depositions of the treating physicians [which the trial court granted]. ‘‘On January 29, 2009, the parties reported back to the court that no additional depositions for the plain- tiff’s Mayo Clinic witnesses had been taken. The defen- dant thereafter repeated its request that, because of undue prejudice and delay in the taking of their deposi- tions, the plaintiff should be precluded from relying on the medical reports of the treating physicians on the issue of causation. [The defendant further contended that the depositions would be pointless because none of the witnesses thus far deposed had offered opinions that the defendant’s conduct had caused Leslie’s injur- ies.] In response, the plaintiff asserted that the medical records themselves were sufficient evidence to estab- lish the cause of Leslie’s cognitive impairments and, on the court’s request, she identified the portions of the medical reports [of both McEvoy and Josephs] that she claimed contained adequate opinions on causation. . . . ‘‘At that point, the court expressed concern over the fact that [the physicians’] impressions appeared to be based exclusively on the plaintiff’s and Leslie’s own reports of the anoxic incident. After much discussion, the court ruled that the Mayo Clinic records, without any supporting testimony, were insufficient to establish a proper foundation for expert medical opinion on cau- sation because they were predicated on layperson opin- ion and inadmissible hearsay. [Nonetheless, the court denied without prejudice the defendant’s motion in limine to preclude the reports or testimony of the Mayo Clinic physicians.] The court, over objection from the defendant, proceeded to grant in part the plaintiff’s motion for the appointment of a commission to permit the taking of McEvoy’s and Josephs’ depositions, and indicated that if those physicians did not testify ade- quately to support the basis of the plaintiff’s theory on causation, their records would only be admissible insofar as they reflected Leslie’s treatment at the Mayo Clinic, with any portions connected to the causation of her injuries being redacted. ‘‘On February 2, 2009, the parties went forward with Josephs’ deposition. At the outset, counsel for the Mayo Clinic, appearing on behalf of Josephs, stated that he would not be opining on the issues of standard of care or causation and that he would only testify as to his care of Leslie as a treating physician. Upon his initial examination by the defendant, Josephs testified, consis- tent with his counsel’s opening remarks, that it was not his intent to give an opinion as to whether the defendant’s care and treatment of Leslie led to an anoxic event and that he was unaware of what in fact caused the anoxia. Additionally, Josephs stated that he had not reviewed the defendant’s records of Leslie’s hospitaliza- tion, and that the circumstances surrounding her anoxic event were relayed to him by Leslie and the plaintiff. ‘‘During the plaintiff’s examination, however, Josephs testified that there was information available to him that indicated that while Leslie was in the care of the defendant her rate of breathing was reduced to some- where between one and four breaths per minute and that upon his review of the materials available to him he concluded that her cognitive deficits were caused by this anoxic event. Although both sides, and the court, were under the assumption that Josephs’ examination would last four hours, counsel for the Mayo Clinic uni- laterally terminated the deposition after the second hour of questioning [each party having approximately equal time]. ‘‘The following day, the plaintiff issued subpoenas seeking to compel the continued deposition of Josephs and the deposition of McEvoy, and counsel for the Mayo Clinic filed a motion for a protective order seeking to preclude the plaintiff from completing Josephs’ deposi- tion and from conducting McEvoy’s deposition, con- tending that these examinations constituted an annoyance and were unduly burdensome. The defen- dant joined in the Mayo Clinic’s motion and, in its sup- plemental brief in opposition to the continued depositions, argued that neither Josephs nor McEvoy could be compelled to testify as to their expert medical opinions on causation. [In light of the plaintiff’s objec- tion that the Mayo Clinic’s motion could not properly be accepted by the court without its counsel having filed an appearance, the court decided, without objection, to address the defendant’s renewed objection to the depositions.] The court agreed [with the defendant] and vacated its previous order [appointing a commission] for the depositions of Josephs and McEvoy. Accord- ingly, the court advised counsel for the Mayo Clinic that Josephs and McEvoy were no longer under subpoena. ‘‘On February 6, 2009, the defendant filed a motion for permission to file a motion for summary judgment. The court granted the motion for permission on Febru- ary 9, 2009, and the defendant filed its motion for sum- mary judgment that day. The court also ordered the plaintiff to file her opposition to the motion the follow- ing day. ‘‘On February 17, 2009, the court heard oral argument on the defendant’s motion for summary judgment. The defendant claimed that it was entitled to summary judg- ment because the plaintiff could not establish the ele- ment of causation by expert testimony. Specifically, it argued that the treating physicians’ opinions contained within their medical reports were insufficient to estab- lish that the alleged injuries were caused by the defen- dant. The court agreed and granted the defendant’s motion for summary judgment.’’ (Footnotes altered.) Id., 85–92. The plaintiff appealed from the judgment to the Appellate Court, claiming that the trial court improperly had: (1) deemed the opinions of the treating physicians in the medical records inadmissible on the issue of causation; and (2) precluded the continuation of Josephs’ deposition and the taking of McEvoy’s deposi- tion in toto, effectively affording the treating physicians a testimonial privilege that is not recognized under Con- necticut law. Id., 84. The Appellate Court agreed with both claims. Id. With respect to the first claim, the Appellate Court determined that the trial court’s ruling that the medical records were inadmissible because the physicians’ statements were predicated on hearsay and recitations of lay opinions was based on a misapprehension of the law rather than a reasoned exercise of discretion. As such, the Appellate Court held that the trial court’s decision could not stand as a proper use of its discre- tion. Id., 95–99. In so holding, the Appellate Court pos- ited that ‘‘our case law is clear that a physician’s medical opinion is not inadmissible because it is formed, in whole or in part, on the basis of hearsay statements made by a patient.’’ Id., 96. The court rejected the propo- sition that it was fatal to the admission of the physicians’ reports that Leslie and the plaintiff had reported the anoxic incident. Id., 97. In doing so, the court concluded that the information available to the physicians— including the results of comprehensive testing of Les- lie’s cognitive functioning at the Mayo Clinic and the investigative report from a state board regarding Les- lie’s 2002 hospitalization—demonstrated that the ‘‘detailed conclusions of the treating physicians . . . were sufficiently reliable to establish that the medical conclusions recorded in the treaters’ reports were more than mere recitations of lay opinions.’’ Id., 97–98. The Appellate Court also rejected alternate grounds raised by the defendant that the treating physicians had not opined on causation with a reasonable degree of medi- cal probability; id., 99–102; and that the defendant had been unable to fully cross-examine the physicians. Id., 102–103. With respect to the plaintiff’s second claim regarding the termination of the commission, the Appellate Court concluded that the trial court had abused its discretion by precluding McEvoy’s deposition after instructing the plaintiff that she could not meet her evidentiary burden without expert testimony.8 Id., 105. In so concluding, the court rejected the defendant’s contention that treating physicians enjoy an absolute privilege not to be pressed into service as experts. Id., 106–109. Accordingly, the Appellate Court reversed the trial court’s judgment in favor of the defendant and remanded the case with direction to deny the defendant’s motion for summary judgment and for further proceedings. Id., 109. Thereafter, this court granted the defendant’s petition for certification to appeal, limited to the following ques- tion: ‘‘Did the Appellate Court properly conclude that the trial court abused its discretion in its failure to admit certain statements contained within medical records to establish a causal connection between [Leslie’s] injuries and the alleged negligence?’’ Milliun v. New Milford Hospital, 302 Conn. 920, 28 A.3d 338 (2011). For the reasons that follow, we answer that question in the affir- mative. I The defendant claims that the Appellate Court misin- terpreted the trial court’s decision and failed to identify what law the trial court had misapprehended when it deemed the reports by McEvoy and Josephs inadmissi- ble. According to the defendant, the trial court did not conclude that a physician is precluded from forming an expert opinion regarding the causes of a patient’s condition on the basis of out-of-court statements made by a patient, but, rather, that a physician may not rely on such statements from someone other than the patient in forming such an opinion. The defendant therefore contends that the trial court properly concluded that the proffered causation opinions were unreliable on the grounds that the report of the anoxic incident was impermissible hearsay because it was supplied by the plaintiff, not Leslie, and because the reports reflected the treating physicians’ uncertainty as to the essential facts relating to the alleged anoxic incident. In response, the plaintiff contends that the defendant itself has mis- characterized the basis of the trial court’s ruling and that the Appellate Court properly concluded that the trial court had abused its discretion in precluding the reports as evidence of causation. We agree with the plaintiff.9 Certain established principles guide our resolution of the defendant’s claims. In a medical malpractice action, ‘‘[e]xpert medical opinion evidence is usually required to show the cause of an injury or disease because the medical effect on the human system of the infliction of injuries is generally not within the sphere of the com- mon knowledge of the lay person.’’ (Internal quotation marks omitted.) Poulin v. Yasner, 64 Conn. App. 730, 738, 781 A.2d 422, cert. denied, 258 Conn. 911, 782 A.2d 1245 (2001); accord Boone v. William W. Backus Hospi- tal, 272 Conn. 551, 567, 864 A.2d 1 (2005). Such expert opinion may be provided through a signed report of a treating physician in lieu of live testimony, as long as the defendant is afforded an opportunity to cross-exam- ine the author of the report. See General Statutes § 52- 174 (b); Practice Book § 13-4 (a) and (d) (1); Struckman v. Burns, 205 Conn. 542, 552, 534 A.2d 888 (1987). Under the rules of evidence governing expert opin- ions generally, ‘‘[t]he facts in the particular case upon which an expert bases an opinion may be those per- ceived by or made known to the expert at or before the proceeding. The facts need not be admissible in evidence if of a type customarily relied on by experts in the particular field in forming opinions on the subject. The facts relied on . . . are not substantive evidence, unless otherwise admissible as such evidence.’’ Conn. Code Evid. § 7-4 (b). ‘‘[I]nadmissible ‘facts’ upon which experts customarily rely in forming opinions can be derived from sources such as conversations, informal opinions, written reports and data compilations. . . . Subsection (b) [of § 7-4 of the Connecticut Code of Evidence] expressly forbids the facts upon which the expert based his or her opinion to be admitted for their truth unless otherwise substantively admissible under other provisions of the Code. Thus, subsection (b) does not constitute an exception to the hearsay rule or any other exclusionary provision of the Code.’’ (Emphasis added.) Conn. Code Evid. § 7-4 (b), commentary; see State v. Copas, 252 Conn. 318, 328, 746 A.2d 761 (2000) (‘‘[a]lthough some of the facts considered by the experts . . . may not [be] substantively admissible . . . the parties [are] not precluded from examining the experts about those facts insofar as they related to the basis for the experts’ opinions’’ [citations omitted]). Thus, ‘‘[w]hen the expert witness has consulted numerous sources, and uses that information, together with his own professional knowledge and experience, to arrive at his opinion, that opinion is regarded as evidence in its own right and not as hearsay in disguise.’’ (Internal quotation marks omitted.) In re Barbara J., 215 Conn. 31, 43, 574 A.2d 203 (1990). Therefore, ‘‘an expert’s opinion is not rendered inad- missible merely because the opinion is based on inad- missible hearsay, so long as the opinion is based on trustworthy information and the expert had sufficient experience to evaluate that information so as to come to a conclusion which the trial court might well hold worthy of consideration by the jury.’’10 (Internal quota- tion marks omitted.) George v. Ericson, 250 Conn. 312, 321, 736 A.2d 889 (1999). The fact that a physician’s report includes hearsay statements, whether from a patient or someone else, would not bar the report’s admission on that basis unless those statements were being offered for substantive purposes, i.e., the truth of the matter asserted.11 Compare Farrell v. Bass, 90 Conn. App. 804, 816–19, 879 A.2d 516 (2005) (concluding that trial court properly precluded plaintiffs’ expert from testifying regarding contents of article written by another physician because article was not being used as factual basis of expert’s opinion but instead to prove truth of matter asserted in article), with State v. Henry, 27 Conn. App. 520, 529–30, 608 A.2d 696 (1992) (rejecting claim that trial court improperly admitted prejudicial hearsay by allowing into evidence eyewit- ness’ statement through psychiatrist’s testimony because statement was introduced not for its truth but to show basis of expert opinion). In the present case, the plaintiff was not offering her own statements and those of Leslie in the reports relaying the 2002 anoxic incident as substantive evi- dence of the fact that Leslie had in fact suffered anoxia while in the defendant’s care and due to the defendant’s negligence. Rather, she was offering those statements as evidence of the information on which Josephs and McEvoy had based their respective diagnoses of anoxic encephalopathy arising from the 2002 incident as the cause of Leslie’s cognitive deficits. Therefore, to the extent that the trial court deemed the reports not to be competent evidence due to the inclusion of hearsay statements, the Appellate Court properly concluded that this determination was predicated on a misappre- hension of the controlling legal principles. With respect to the reliability of those statements as a basis on which to form a medical opinion, which is a proper consideration; George v. Ericson, supra, 250 Conn. 322; the only concern articulated by the trial court that might have any bearing on this matter was the court’s view that the physicians’ reports contained nothing more than impermissible expert opinion from lay witnesses on the issue of causation. We find several defects in this reasoning. It appears that the trial court focused exclusively on the fact that the reports indi- cated that Leslie or the plaintiff had reported the ‘‘anoxia,’’ or ‘‘anoxic’’ incident, to the physicians and assumed: (1) that Leslie and the plaintiff actually used this diagnostic term, as opposed to the indicia of that term, to characterize the 2002 incident in their meetings with the physicians; and (2) that the reports’ recitation of those statements reflected the physicians’ obsequi- ous acceptance of that ‘‘diagnosis’’ without ascertaining the underlying facts and without bringing any indepen- dent judgment to bear on the question of whether an anoxic incident during Leslie’s July, 2002 hospitaliza- tion had caused her cognitive impairments. Given the Mayo Clinic’s well established reputation as a preemi- nent medical facility, such assumptions, devoid of fac- tual predicates that would support them, seem dubious. More importantly, however, these assumptions are con- tradicted by the reports when reviewed in their entirety.12 ‘‘Expert opinions must be based upon reasonable probabilities rather than mere speculation or conjecture if they are to be admissible in establishing causation.13 . . . To be reasonably probable, a conclusion must be more likely than not. . . . Whether an expert’s testi- mony is expressed in terms of a reasonable probability . . . does not depend upon the semantics of the expert or his use of any particular term or phrase, but rather, is determined by looking at the entire substance of the expert’s testimony. . . . [Similarly, when] reports are the substitute for testimony, the entire report should be examined, not only certain phrases or words.’’ (Cita- tions omitted; emphasis added; footnote added.) Struckman v. Burns, supra, 205 Conn. 554–55. Thus, the trial court was obliged to consider the reports in their totality to determine whether they were competent evidence as to whether the defendant’s acts or omissions had caused Leslie’s cognitive impairment rather than focus on a particular word or phrase. Cf. Mather v. Griffin Hospital, 207 Conn. 125, 134–36, 540 A.2d 666 (1988) (concluding that testimony of three expert witnesses collectively was sufficient to establish causation). When considered in the fullness of their content, those reports reflect the following information. The plaintiff and Leslie had provided the Mayo Clinic with information that, prior to Leslie’s 2002 hospitaliza- tion, she had been on considerable amounts of Valium without any decline in cognitive functioning. While an in-patient at the defendant and while still taking Valium, Leslie went for a period of time breathing at a rate of somewhere between one and four breaths per minute. This event was witnessed by a nurse, but was not treated aggressively.14 Although Leslie’s cognitive function appeared normal up to one hour before this period of respiratory dysfunction, almost immediately thereafter her family noticed severe cognitive deficits.15 By 2005, Leslie and the plaintiff described Leslie’s cognitive func- tioning as static or slightly improved from the substan- tial decline in functioning that occurred in July, 2002. McEvoy’s February, 2005 report stated: ‘‘It is still my clinical impression based on the temporal profile of the onset of her symptoms, that [Leslie] has a primary autoimmune disorder consistent with [SMS], which by history was associated with dysarthria but no cognitive impairment, along with a superimposed anoxic enceph- alopathy which developed by her report of July 10, 2002, in [a] hospital in Connecticut at the time of uncontrolled muscle spasms from her SMS. Her cognitive function, by her and [the plaintiff’s] report, has improved and pretty much stabilized, as might be expected after an anoxic [incident].’’ (Emphasis added.) These records further reflect that McEvoy thereafter directed Leslie to various clinicians for extensive cogni- tive and neurological testing. Following his own testing and physical examination of Leslie, as well as a review of the history obtained by Dupont, Josephs’ March, 2005 report stated more definitively: ‘‘It is my opinion that [Leslie’s] cognitive impairment is secondary to what- ever event occurred or whatever transpired in 2002. The family member tells me that there was anoxia and that there was a change after that event. Therefore, one must conclude that her cognitive impairment was secondary to the event that occurred in 2002. Arguing for this being the process of her cognitive impairment also is the fact that she has not had any significant progression since 2002. The cognitive impairment in my opinion is not related to [Leslie’s] diagnosis [of SMS] and is not in keeping with a neurodegenerative syn- drome given the lack of progression.’’ (Emphasis added.) In the ‘‘Diagnoses’’ section of the report, Josephs listed ‘‘[c]ognitive impairment (static encepha- lopathy secondary to anoxic brain damage).’’ Following her review of the diagnostic impressions of Josephs and others who had examined and tested Leslie, McEvoy similarly adopted as her diagnosis in her March, 2005 report ‘‘Cognitive impairment (static encephalopathy secondary to anoxic brain damage).’’ These records reflect that McEvoy and Josephs con- cluded that they had sufficient, reliable information to diagnose Leslie’s condition and the cause of that condi- tion with the requisite degree of confidence. The physi- cians ruled out Leslie’s SMS or some other neurodegenerative condition as the cause of those injur- ies and apparently concluded that the anoxic incident, as described, was the presumptive cause of Leslie’s cognitive deficits because such a causal relationship was consistent with the timing of the onset of symp- toms, the symptoms manifested and the results of com- prehensive examination and testing. Such a deductive process is a proper method on which to base an opinion as to causation. See Struckman v. Burns, supra, 205 Conn. 554 (‘‘[t]he causal relation between an injury and its later physical effects may be established by the direct opinion of a physician, by his deduction by the process of eliminating causes other than the traumatic agency, or by his opinion based upon a hypothetical question’’ [emphasis added]); see also Klein v. Norwalk Hospital, 299 Conn. 241, 252, 9 A.3d 364 (2010) (‘‘differential diagnosis is a method of diagnosis that involves a deter- mination of which of a variety of possible conditions is the probable cause of an individual’s symptoms, often by a process of elimination’’ [internal quotation marks omitted]). Although there may be other possible causes that the physicians did not consider, such matters go to weight, not admissibility.16 See Eisenbach v. Downey, 45 Conn. App. 165, 176, 694 A.2d 1376 (concluding that defendants’ argument that trial court improperly admit- ted medical reports to establish causal connection because reports did not consider and eliminate plain- tiffs’ prior injuries as cause, went to weight and not admissibility), cert. denied, 241 Conn. 926, 696 A.2d 1264 (1997). The defendant contends, however, that Josephs’ use of the phrase ‘‘whatever event occurred or whatever transpired in 2002’’ and McEvoy’s recitation of ‘‘an apparent anoxic event’’ reflect uncertainty as to the essential facts on which any purported causation opin- ion was predicated. We note that the trial court identi- fied no such concerns as a basis for its decision. Moreover, we view these terms simply as the physicians’ acknowledgment that, because they did not have inde- pendent verification of the facts provided, they were assuming the truth of those facts for the purpose of rendering a diagnosis. Indeed, in this regard the trial court’s reasoning and the defendant’s positions in support thereof suffer from a similar defect. Neither the trial court nor the defen- dant has brought any authority to our attention, and we are aware of none, that would require the plaintiff to establish the truth of all of the foundational facts on which the expert relies through the expert’s testimony. There is, however, authority to the contrary. See Hally v. Hospital of St. Raphael, 162 Conn. 352, 358–59, 294 A.2d 305 (1972) (citing authority for proposition that jury is not obligated to accept ultimate opinion of expert witnesses ‘‘since the jury might reject the opinion . . . because the opinion was based on subordinate facts which they do not find proven’’); see also Conn. Code Evid. § 7-4 (a), commentary (‘‘Subsection [a] contem- plates that disclosure of the ‘foundational’ facts will, in most cases, occur during the examination undertaken by the party calling the expert and before the expert states his or her opinion. The requirement of prelimi- nary disclosure, however, is subject to the trial court’s discretionary authority to admit evidence upon proof of connecting facts, or subject to later proof of connecting facts.’’). The plaintiff readily acknowledges that she will have to establish, through witnesses with personal knowledge of the circumstances, that the defendant’s acts or omissions actually caused Leslie to suffer respi- ratory distress. Accordingly, we conclude that the Appellate Court properly determined that the trial court had misapprehended the law in concluding that the reports did not contain competent evidence to create a material issue of dispute as to causation. II The defendant asserts a second ground on which it claims that the Appellate Court improperly concluded that the trial court’s decision to preclude the reports was an abuse of discretion. This claim, variously stated, challenges the Appellate Court’s conclusions relating to the trial court’s decision to withdraw its previous order granting the plaintiff’s motion for the appointment of a commission, which effectively quashed the subpoe- nas compelling Josephs and McEvoy to submit to the depositions. Analyzing this claim through a slightly dif- ferent framework than applied by the Appellate Court, the defendant contends that: (1) the trial court properly determined that the Mayo Clinic physicians had a testi- monial privilege against being compelled to testify as expert witnesses on causation; (2) as a result of their effective invocation of that privilege, the defendant was deprived of an opportunity to cross-examine the plain- tiff’s experts; and (3) the trial court properly condi- tioned the admission of the reports on the availability of the plaintiff’s experts in part due to prejudice to the defendant if such an opportunity was not afforded.17 In defense of the trial court’s decision regarding the testimonial privilege, the defendant contends that case law from our Superior Court as well as from other jurisdictions supports the conclusion that compelling a physician to serve the interests of a private litigant is tantamount to involuntary servitude prohibited under the thirteenth amendment to the United States constitu- tion because it requires the physician to provide for free a commodity that has value, namely, the physician’s expertise. The defendant further contends that, in order to justify abrogating this privilege in light of these sub- stantial interests, there must be a compelling necessity for the testimony. Because there is no basis in the record on which to conclude that the plaintiff could not have procured any experts other than her treating physicians to opine on causation to demonstrate such a compelling necessity, the defendant contends that the trial court properly terminated the commission. We conclude that the defendant was not deprived of an opportunity for cross-examination. In light of the facts in the record supporting that conclusion and repre- sentations from counsel at oral argument before this court, we further conclude that it is unnecessary to examine the Appellate Court’s determination that the trial court improperly ruled that Leslie’s treating physi- cians could not be compelled to provide expert testi- mony with regard to opinions expressed in the reports. We begin by noting that the trial court did not cite this ground as a basis for rendering summary judgment in the defendant’s favor. The sole stated basis for the judgment was that there was ‘‘nothing in the records, nor any other evidence, to indicate that the person(s) who had made the comments to the treating physicians, advocating a causal connection between [Leslie’s] symptoms and her stay at the [defendant], were quali- fied to give expert testimony regarding causation.’’ Even if we were to consider the defendant’s claim as a prop- erly raised alternate ground for affirmance, however, the defendant cannot prevail. The record reveals the following additional facts. At the outset of Josephs’ deposition, the defendant elicited responses indicating that Josephs had neither been retained by the plaintiff to provide expert testimony nor been informed that his opinions and records would be used as expert testimony. Immediately thereafter, the defendant reiterated for the record its objections to the depositions as burdensome, expensive and preju- dicial. It further stated an objection on the ground that a physician cannot be compelled to provide expert testi- mony, citing Superior Court case law as support.18 In response, Joanne L. Martin, counsel for the Mayo Clinic, stated that Josephs and the Mayo Clinic had the under- standing that Josephs was there solely to testify as to ‘‘his care and treatment of [Leslie] and not to render expert opinions that go to standard of care [or] causa- tion . . . .’’ The defendant then elicited responses from Josephs indicating that he did not intend to offer testi- mony outside the scope of the matters reflected in Les- lie’s medical records as regard to her care and treatment or to offer any opinion as to the cause of any problems she claims to have suffered as a result of the defendant’s conduct. Thereafter, the defendant examined Josephs at length about t