Opinion ID: 3008296
Heading Depth: 3
Heading Rank: 1

Heading: Lay Testimony of Causation

Text: Lay testimony may be used as evidence of causation in certain circumstances, but “[w]hen expert testimony is required, lay evidence supporting liability is legally insufficient.” City of Keller , 168 S.W.3d at 812 . In medical malpractice cases, expert testimony regarding causation is the norm: “The general rule has long been that expert testimony is necessary to establish causation as to medical conditions outside the common knowledge and experience of jurors.” Guevara v. Ferrer , 247 S.W.3d 662, 665 (Tex. 2007); see also Bowles v. Bourdon , 219 S.W.2d 779, 782 (Tex. 1949) (“It is definitely settled with us that a patient has no cause of action against his doctor for malpractice, either in diagnosis or recognized treatment, unless he proves by a doctor of the same school of practice as the defendant: (1) that the diagnosis or treatment complained of was such as to constitute negligence and (2) that it was a proximate cause of the patient’s injuries.”). We have allowed lay evidence to establish causation “in those cases in which general experience and common sense will enable a layman to determine, with reasonable probability, the causal relationship between the event and the condition.” Morgan , 675 S.W.2d at 733 (citing Lenger v. Physician’s Gen. Hosp., Inc. , 455 S.W.2d 703, 706 (Tex. 1970)). Care must be taken to avoid the post hoc ergo propter hoc fallacy, that is, finding an earlier event caused a later event merely because it occurred first. Stated simply, correlation does not necessarily imply causation. As we noted in Guevara , “[e] vidence of an event followed closely by manifestation of or treatment for conditions which did not appear before the event raises suspicion that the event at issue caused the conditions. But suspicion has not been and is not legally sufficient to support a finding of legal causation.” 247 S.W.3d at 668. When lay testimony is credited as evidence of causation, it usually highlights a connection between two events that is apparent to a casual observer. In Morgan , for example, a previously healthy employee, upon exposure to leaking chemicals, suffered watering of the eyes, blurred vision, headaches, and swelling of the breathing passages. 675 S.W.2d at 733. In such a circumstance, lay testimony sufficed to connect the specific injury to the negligence with no evidence of causation beyond the leaking chemicals. Id. Likewise in Guevara , we stated that determining causation of “certain types of pain, bone fractures, and similar basic conditions” following an automobile accident was within the competence of lay jurors. 247 S.W.3d at 668. But we held that expert testimony was required to prove that a patient’s medical expenses resulted from the accident, noting that “[p] atients in hospitals are often treated for more than one condition brought on by causes independent of each other.” Id. at 669. These cases illustrate this basic premise: “[N]on-expert evidence alone is sufficient to support a finding of causation in limited circumstances where both the occurrence and conditions complained of are such that the general experience and common sense of laypersons are sufficient to evaluate the conditions and whether they were probably caused by the occurrence.” Id. at 668. The present case does not fall within this rule. Unlike in Morgan , an otherwise healthy person did not suddenly experience health difficulties following the defendant’s negligent conduct when the plaintiff’s symptoms were reasonably attributable to the negligence and to nothing else. Rather, a patient with terminal colon cancer did not receive antibiotics for four-and-a-half days following major abdominal surgery and after having received the medications for eight days. There is no direct evidence that she suffered from an infection treatable by the omitted antibiotics, but there is evidence that she had two other infections that accounted for all of her symptoms during that time. Given Casas’s medical condition, expert testimony was crucial to link the prescription lapse to an infection causing additional pain and suffering beyond what she would otherwise have experienced. See Kaster v. Woodson , 123 S.W.2d 981, 983 (Tex. Civ. App.—Austin 1938, writ ref’d ) (“What is an infection and from whence did it come are matters determinable only by medical experts.”); see also Hart v. Van Zandt , 399 S.W.2d 791, 792 (Tex. 1966) (“In determining negligence in a case such as this, which concerns the highly specialized art of treating disease, the court and jury must be dependent on expert testimony. There can be no other guide, and where want of skill and attention is not thus shown by expert evidence applied to the facts, there is no evidence of it proper to be submitted to the jury.”). The Casases point to testimony by Casas’s husband and son to support their argument that she deteriorated rapidly after discovering she did not receive the antibiotics. But this characterization overstates the evidence. While Casas’s husband testified she was upset and did not trust her doctors following the discovery, she was still determined to fight her cancer. The son also observed Casas’s anger and lack of trust but testified that the opening of her wound, which occurred the same day she learned of the lapse, upset her even more. As Dr. Daller admitted, Candida likely caused the abscess that required Dr. Garcia-Cantu to drain the wound. Further, based on his experience at Casas’s bedside, her son pinpointed the tragic events of September 11, 2001, and their effect on his mother as the turning point in her mental state. The latter event was some seven weeks after discovery of the lapsed prescriptions and after Casas’s discharge from and re-admission to the Hospital. This evidence does not bear out the Casases ’ claim of a marked shift in Casas’s mental resilience following the omission of the medications. More importantly, Casas’s husband and son were unable to precisely identify the cause of her suffering. While they could accurately describe her discomfort, they were unable to say if it was the cancer, the surgery, the other infections, or the lapse that caused it. Even testimony that Casas suffered after learning of the omission raises no more than a mere suspicion of causation, and that is not enough, see Guevara , 247 S.W.3d at 668, particularly in light of the evidence that Casas thought she was cured of cancer before the surgery and then learned that not only was it “back with a vengeance,” it was terminal. The testimony of Casas’s husband and son is evidence of her suffering, but not of its cause. Thus, we hold that the lay testimony presented by the Casases is legally insufficient to establish that the Hospital’s negligence caused Casas additional pain and suffering.