A Preponderance of the Evidence (a Cautionary Tale)
October 6, 2011 in Medical Legal
It’s unclear how many non-legal persons actually understand how different civil trials are from criminal proceedings. Most people have heard that juries in criminal trials are told that they can only find a defendant guilty if their belief that the defendant is guilty is beyond a reasonable doubt. Federal courts define this term further as, “proof of such a convincing character that a reasonable person would not hesitate to act upon it in the most important of his own affairs.” Many legal specialists quantitatively define this term as a 98% or 99%” certainty of guilt.
Most people are less likely to know that the burden of proof in a civil trial is far less. In legal parlance, this is stated as a “preponderance of the evidence”. Quantitatively stated, this is a greater than 50% weight of the evidence for one side or the other. In layman’s terms, it’s more likely than not that one side is guilty. But there can still be a 49% range of doubt. Additional definitions include, ” just enough evidence to make it more likely than not that the fact the claimant seeks to prove is true.”
It’s understandable that criminal trials have such a high burden of proof in convicting the defendant given what is at stake. Not being a legal scholar, it’s not at all clear why this standard is so drastically lowered for civil trials. Maybe it’s because civil trials were traditionally considered to be more straight forward and easy to prove or disprove. But they are not. Certainly in the case of medical malpractice the issues are complex and a lack of definitive evidence can be misconstrued by a jury to be evidence to the contrary. I’ll give an example.
A nurse recently told me about an incident many years ago. An older female had been admitted to the hospital with a heart attack. She had been evaluated, treated, and stabilized appropriately per standards of care and was doing well. The night prior to her scheduled discharge she was being monitored on a telemetry floor and while eating dinner she had sudden onset of shortness of breath. She called the nursing station and was immediately evaluated. Within a minute she became unresponsive and went into cardiac arrest. Initially believing that she may be choking on her dinner the staff tried abdominal thrusts and clearing of her mouth and airway but no food or obstruction was found.
Simultaneously CPR was begun and the patient was intubated (a breathing tube placed through the mouth and into the trachea). They found it was extremely difficult to ventilate the patient (i.e. to use a bag to manually force air through the endotracheal tube into the lungs) and despite their heroic efforts the patient was unable to be resuscitated.
Lawsuits for choking deaths in hospitals and other health care facilities are favorites for families because the concept is easy to understand and they believe it to be near 100% avoidable. Had this case been litigated, there is no doubt that the plaintiffs attorney would have argued that quite obviously this patient died from choking and from the negligence of the staff and physicians. It would have been stated that the patient should not have been given solid food to eat because of her advanced age or because she did or did not have her dentures provided to her or because the heart attack had made her weak and she should have been evaluated by a speech therapist prior to being given solid food or one or more of her medications depressed her mental status or made her weak so that she was unable to swallow normally or so on and so forth. There would have been no direct or definitive proof for any of these claims but “specialists” would have provided testimony (actually their opinions) that any one of these factors is plausible so that enough doubt is placed into the minds of the jury.
Then the attorney for the plaintiff would have argued that in trying to clear the patient’s mouth the staff actually pushed the food bolus further down into the windpipe. And then it was pushed even further down during the intubation so there was no hope of it being removed and that it completely blocked the airway. The inability to ventilate the patient through the tube will be given as “proof” that the airway was totally obstructed with food.
Granted, there was no definitive proof for any of this. Scientists would call this argument a “theory” but NOT proof and would certainly try to follow this up with actual . . you know. . evidence. But in the make-believe land of civil litigation, a preponderance of the evidence could easily be interpreted by the jury as a preponderance of doubt in the defense’s claim that the patient didn’t choke. I.e. the plaintiff’s argument seems so reasonable and plausible and all the defense can do is to deny it. Even if this case never went to trial it would have been an excellent candidate to settle out of court.
But this case never went to litigation. The family of the patient decided to get an autopsy. Why? I don’t know. Maybe they really were looking for the truth. Maybe they were looking for the food impacted into and blocking the airway just to make the case that much easier. But instead what they found was the truth.
It turns out that the left side of the patient’s heart had been weakened so much by the heart attack that the wall of the left ventricle literally and suddenly split open. Blood poured out under high pressure into a space surrounding the heart called the pericardium. A thin membrane normally surrounds the heart like a balloon and as the blood poured into this virtual space, pressure built up and squeezed the heart so much that it was unable to beat anymore and stopped. This happened within seconds and is what caused the initial symptoms of shortness of breath. As more blood filled the area around the heart, this increased pressure was transmitted to the chest cavity including the airways and lungs thus making it very difficult to pump air into her lungs against this pressure.
Rupture of the free wall of the left ventricle following a heart attack is unusual and occurs in less than one percent of cases. It is unpredictable and can occur despite appropriate and timely treatment for heart attack. Emergent surgery is usually the only treatment option but the mortality rate is very high especially in severe cases as this one. In short, no one was to blame.
This example typifies why physicians and other health care works don’t feel like the current civil litigation system is fair or protects them against malicious and baseless litigation. Most malpractice cases in this country are filed not because of actual provable malpractice, but because of an unexpected and severe outcome regardless of fault. Plantiff’s attorneys threaten to pervert the principle of a preponderance of the evidence into a preponderance of doubt for juries made up of people with the same level of expertise in the complexities of health care as Joe the Plumber. Many of these cases are settled out of court for this very reason.
What is needed is tort reform so that plaintiffs attorneys cannot hope to game the system by taking advantage of weak burden of proof requirements and gullible juries. What is needed is a system of specialized malpractice courts with sitting impartial panels of medical and legal experts and consumer and patient care advocates. A panel that would reasonably be expected to believe that the odds of a patient choking who has no risk factors for choking are far less than the odds that a catastrophic cardiovascular event occurred in a patient only a few days removed from a heart attack. A panel would be more likely to understand that a theory is not evidence and doubt is not evidence to the contrary.