We hold that the common law sudden emergency doctrine is not an affirmative defense within the meaning of Indiana Trial Rule 8(C) that requires affirmative defenses to be pleaded in a defendant's answer. We also hold that in cases where the defendant seeks a failure to mitigate damages instruction based on a plaintiff's failure to follow a treating doctor's recommendations, whether expert medical opinion testimony is required is to be determined on a case-by-case basis.
Factual and Procedural Background
On May 8, 1996, Christopher Wester-field rear-ended Ann Willis' van as it was stopped at a red light. Westerfield told the officer taking the accident report that he was unable to stop in time to avoid striking Willis' vehicle. Two and one-half years after the collision, Westerfield testified in a deposition that Ann Willis sud *1183 denly and without warning changed lanes and applied her brakes at the intersection and that he was unable to stop his vehicle before it struck Willis' vehicle because of wet pavement and Willis' quick lane change.
In December 1997, Ann and Jeff Willis filed their complaint for damages against Westerfield. Westerfield initially filed an answer in which he pleaded contributory negligence as an affirmative defense. He later amended his answer to replace his contributory negligence defense with a request for allocation of fault pursuant to Indiana's Comparative Fault Act. Neither the answer nor the amended answer mentioned the sudden emergency doctrine.
At trial, the court admitted the entire video-taped deposition of Ann Willis's treating physician, Dr. Robert K. Silbert, after denying Willis' motion to strike the portions of Westerfield's eross-examination of Dr. Silbert that referred to Ann's preexisting conditions, subsequent conditions, or conditions unrelated to her collision injuries. On direct-examination, Dr. Sil-bert's deposition included his opinion that Ann did nothing after the collision to aggravate or worsen her injuries. On cross-examination, Dr. Silbert testified that Ann had failed to pursue recommended physical therapy and "in that particular condition she didn't help herself." Westerfield relied on his cross-examination of Dr. Sil-bert and did not call his own medical expert.
At the close of evidence, Westerfield tendered jury instructions on the sudden emergency doctrine, the affirmative defense of failure to mitigate damages, and allocation of fault under Indiana's Comparative Fault Act. The Willises objected to the sudden emergency instruction on the ground that Westerfield had waived that defense by failing to raise it in his responsive pleadings. The trial court overruled the objection and gave all three instructions.
Following a three day trial, the jury returned a verdiet in favor of the Willises, awarding them $5,000 in compensatory damages without regard to fault. Based on a finding that Ann was fifty percent at fault, the $5,000 verdict was reduced to $2,500 in accordance with Indiana's Comparative Fault Act.
The Willises appealed seeking a new trial as to damages only. They raised four grounds. First, they asserted the trial court erred in instructing the jury on the sudden emergency doctrine because Wes-terfield failed to raise the doctrine in his pleadings. Second, they asserted the trial court erred in instructing the jury on failure to mitigate damages because Wester-field failed to present medical expert testimony supporting that defense. Third, they asserted the trial court erred in denying their motion to strike portions of Wes-terfield's cross-examination of Dr. Silbert. Fourth, they alleged the trial court erred in giving an instruction on allocation of fault under Indiana's Comparative Fault Act. They contended that Westerfield's amended answer removing contributory negligence as a defense withdrew contributory negligence as an issue in the case and thereby eliminated any issue of fault by Willis.
The Court of Appeals initially affirmed the trial court. Willis v. Westerfield,
On rehearing, the Court of Appeals reconsidered its view of the need for expert medical opinion testimony on the defense of failure to mitigate damages and held that an instruction on that issue was error. Willis v. Westerfield,
I. Sudden Emergency Doctrine
In a negligence cause of action, the sudden emergency doctrine is an application of the general requirement that one's conduct conform to the standard of a reasonable person. The emergency is simply one of the cireumstances to be considered in forming a judgment about an actor's fault.
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The doctrine was developed by the courts to recognize that a person confronted with sudden or unexpected circumstances calling for immediate action is not expected to exercise the judgment of one acting under normal cireumstances. See W.P. Keeton, D. Dobbs, R. Keeton & D. Owen, Prosser and Keeton on the Law of Torts § 338 at 196 (5th ed.1984). The basis of the doctrine is that "the actor is left no time for adequate thought, or is reasonably so disturbed or excited that the actor cannot weigh alternative courses of action, and must make a speedy decision, based very largely upon impulse or guess. Under such conditions, the actor cannot reasonably be held to the same accuracy of judgment or conduct as one who has had full opportunity to reflect, even though it later appears that the actor made the wrong decision, one which no reasonable person could possibly have made after due deliberation." Id. In Indiana, a defendant seeking a sudden emergency instruction must show that three factual prerequisites have been satisfied: 1) the defendant must not have ereated or brought about the emergency through his own negligence; 2) the danger or peril confronting the defendant must appear to be so imminent as to leave no time for deliberation; and 3) the defendant's apprehension of the peril must
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itself be reasonable. Sullivan v. Fairmont Homes, Inc.,
Indiana Trial Rule 8(C) does not specifically refer to sudden emergency. It provides that "A responsive pleading shall set forth affirmatively and carry the burden of proving: [list of defenses] and any other matter constituting an avoidance, matter of abatement, or affirmative defense." Pursuant to this Rule, a party seeking the benefit of an affirmative defense must raise and specifically plead that defense or it is waived. Freedom Express, Inc. v. Merch Warehouse Co., Inc.,
Some Indiana decisions have described the sudden emergency doctrine as an affirmative defense.
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However, no case has found this defense waived pursuant to Trial Rule 8(C) for failure to plead it. The Court of Appeals observed that these references to sudden emergency as an affirmative defense may have been the result of "muddied language," and noted that no case addressed whether the proponent must include sudden emergency in a responsive pleading or risk waiving it. Willis,
The sudden emergency doctrine does not impose a lesser standard of care on a person presented with an emer-geney. D. Dobbs, 1 The Law of Torts, § 129 at 804 (West 2001). The individual is still expected to respond to the situation as a reasonably prudent person under the circumstances. The emergency is merely one of the circumstances to be considered in determining whether the actor's conduct was reasonable under all of the cireum-stances. ' Keeton, supra, at 196-97. Thus, a person may be found negligent if his actions are deemed unreasonable, despite the emergency. Id. As the .Court of Appeals stated in Compton v. Pletch,
The sudden emergency instruction informs the jury ... how it is to allocate fault and apportion damages when the conduct of the person in question is that of an "ordinarily prudent person" when faced with an emergency situation. If the conduct of the person conforms to that standard, then the sudden emer-geney instruction informs the jury that the person is to be considered "not negligent" even though another course of action might have prevented the accident.
Viewing the sudden emergency doctrine as an affirmative defense under Rule 8(C) is at odds with these basic tort law principles. The sudden emergency doctrine does not accept the essential allegations of a plaintiff's negligence complaint. Rather it teaches that facts constituting an emer-geney are to be considered by the jury in determining whether the defendant's actions were reasonable under the circumstances. Finally, the Court of Appeals concluded that a mandatory pleading requirement for the sudden emergency doctrine would promote fairness by "minimizing the chances of trial by ambush" and would allow for better preparation of suits, thereby promoting. judicial efficiency. Willis,
II. Failure to Mitigate Damages
On transfer, the Willises argue that the trial court improperly instructed the jury on the affirmative defense of failure to mitigate damages because Wester-field did not produce expert medical opinion testimony that ' Aun's post-collision failure to follow physician-recommended treatment aggravated or increased her injuries. They contend that expert testimony is required to support such a defense, and in its absence an instruction on failure to mitigate was not supported by the evidence. The Court of Appeals initially rejected this claim, concluding that Wes-terfield's theory of the case-that Ann's failure to attend all physician-recommended physical therapy sessions in
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creased her pain and suffering-was within the understanding of a lay person. Willis,
"[TJhe principle of mitigation of damages addresses conduct by an injured party that aggravates or increases the party's injuries." Deible v. Poole,
The Court of Appeals took several recent cases to hold that proof of a failure to mitigate damages defense based on a plaintiff's failure to follow the advice of his or her treating physician requires the defendant to produce medical expert testimony, either through cross-examination of the plaintiff's expert witness or by presenting his or her own expert witness. In some cases, the tendered evidence was merely that the plaintiff had missed some scheduled treatments. 5 In others, there was no evidence establishing that the plaintiff's conduct caused any aggravation of injuries. 6 We agree that in many cases, *1188 expert testimony may be required to establish either the fact or the degree of aggravation of injury arising from failure to follow prescribed medical treatment. But that is not universally the case.
To the extent these cases suggest that expert testimony is always required, we believe that they overstate the evidence required to warrant a mitigation of damages instruction. The affirmative defense of failure to mitigate damages has two elements, and as to both the defendant bears the burden of proof by a preponderance of the evidence. First, the defendant must prove that the plaintiff failed to exercise reasonable care to mitigate his or her post-injury damages. Second, the defendant must prove that the plaintiff's failure to exercise reasonable care caused the plaintiff to suffer an identifiable item of harm not attributable to the defendant's negligent conduct. In this respect, the defendant bears the same burden with respect to this defense that the plaintiff bears with respect to the claim for damages. It is not enough to establish that the plaintiff acted unreasonably. The defendant must establish resulting identifiable quantifiable additional injury, just as the plaintiff must prove harm resulting from the defendant's acts. When, as here, a defendant claims that after an accident a plaintiff unreasonably failed to follow medical advice, in order to establish a failure to mitigate, the defendant must also prove that the plaintiff's actions caused the plaintiff to suffer a discrete, identifiable harm arising from that failure, and not arising from the defendant's acts alone.
The cases expressing a requirement of medical expert opinion testimony as to causation, reflect a concern that jurors may confuse correlation with causation, or may find for a defendant based on mere speculation that some of a plaintiff's injuries are attributable to the plaintiff's failure to follow treatment advice. We agree that these are legitimate concerns and agree that expert testimony will often be required to establish that the plaintiffs conduct caused any additional harm, and if so, how much. However, we do not believe that the causation analysis with respect to failure to mitigate damages defense always requires expert medical testimony. In the context of analyzing the proof required of a plaintiff alleging personal injuries, Johnson v. Bender,
In reviewing a trial court's decision to give or refuse a tendered instruction, this Court considers whether the instruction (1) correctly states the law, (2) is supported by the evidence in the record, and (8) is covered in substance by other instructions. The trial court has discretion in instructing the jury, and we will reverse on the last two issues only when the instructions amount to an abuse of discretion. Wal-Mart Stores, Inc. v. Wright,
As a practical matter, the case-by-case approach will often lead to the same result as the bright line approach taken by the Court of Appeals. The trial court does not rule on whether to give a tendered instruction until after the close of evidence. A party presenting a failure to mitigate damages defense without expert testimony on causation will do so at his or her own peril. If, as is the case before us, the plaintiff's case-in-chief includes testimony from the plaintiff's treating doctors that the plaintiff failed to follow treatment advice but that failure did not cause increased injury, rebutting expert testimony will be required both to ensure a jury instruction on mitigation and ultimately to prevail on the issue before the jury.
In this case, the trial court erred in giving a failure to mitigate instruction because Westerfield failed to carry his burden to prove that Ann's post-injury disregard of advice as to treatment increased Ann's harm, and if so, by how much. On direct-examination, Dr. Silbert testified as follows:
Q: Has Ann Willis done anything unreasonable following her May 9, 1996, motor vehicle collision to aggravate or worsen her accident-related injuries in any way, in your opinion?
A: No she has not.
With respect to Ann's alleged failure to attend recoramended physical therapy sessions after the collision, Dr. Silbert testified on cross examination by Westerfield:
*1190 Q: And so if they don't follow your recommendation to go to physical therapy when prescribed, they're not helping themselves, correct?
A: In that particular condition she didn't help herself.
Westerfield did not produce his own medical expert opinion testimony and argues that this cross-examination testimony was sufficient to warrant an instruction on failure to mitigate damages. We disagree. Applying the principles enunciated above, we find a failure to mitigate instruction inappropriate on these facts because Wes-terfield failed to carry his burden to show how Ann's alleged failure to follow Dr. Silbert's recommendation that she seek physical therapy increased her harm, and if so, by any quantifiable amount or specific item. Accordingly, we vacate the judgment as to damages and remand for a new trial on the issue of damages only.
III. Refusal to Redact Portions of Video Deposition Testimony
The Willises claim that the trial court erred by denying their motion to redact portions of the video deposition testimony of their medical expert Dr. Silbert. They argue that they were unduly prejudiced by the jury's exposure to those parts of the deposition where defense counsel allegedly inquired into Ann's physical condition, pre-existing conditions, subsequent conditions and other unrelated conditions for which defense counsel knew no medical expert evidence of causation existed that causally linked the asserted conditions to the plaintiff's collision injuries. Willis,
IV. Allocation of Fault
The Willises claim the trial court erred in allowing Westerfield to present evidence of Willis' fault and in allowing the jury to determine fault under Indiana's Comparative Fault Act. The Willises argue that when Westerfield sought leave to amend his answer to replace a contributory negligence argument with a request for allocation of fault under the Comparative Fault Act, Westerfield thereby implicitly conceded complete responsibility for the accident. There was no merit to this claim. The Court of Appeals properly held that Westerfield withdrew his affirmative defense of contributory negligence because the Indiana Comparative Fault Act governed this case and not because he was conceding he was completely at fault for the accident.
On transfer Westerfield also urges this Court to address allocation of fault. He argues that under the Comparative Fault Act, whether a plaintiff failed to mitigate damages is an allocation of fault issue. After Westerfield filed his Petition For Transfer, this Court ruled that mitigation of damages is an affirmative defense that may reduce the amount of damages a plaintiff is entitled to recover, but does not affect the ultimate issue of liability. Kocker,
Conclusion
Transfer is granted. The judgment of the trial court as to liability is affirmed. The judgment as to damages is vacated and this case is remanded for a new trial on the issue of damages only.
Notes
. The trial court's sudden emergency instruction directed the jury that it "may not find the Defendant negligent" if it found Westerfield was confronted with a sudden emergency and responded as an ordinarily prudent person. Because the jury found Westerfield negligent, the Court of Appeals concluded "that the jury did not predicate its verdict on the erroneous instruction." Willis,
. See, eg., Regenstreif v. Phelps,
. In Evans v. Palmeter, 521 NE.2d 316, 317 (Ind.1988), this Court reviewed a claim that a trial court gave a sudden emergency instruction based on insufficient evidence. In dicta, this Court stated that "the sudden emergency doctrine is an affirmative defense." See also Aldana v. Sch. City of E. Chicago,
. The Willises did not allege that the instruction incorrectly stated the law, was unsupported by the evidence, or was substantively covered by other instructions. Nor do they contend it unduly emphasized one aspect of the evidence. Accordingly, we do not address any of these issues.
. See, eg., Sikora v. Fromm,
. Wilkinson v. Swafford,