Fundamental in a medical malpractice lawsuit is determining whether an unfortunate outcome is an error of nature or a medical error. An error of nature results from a medical intervention that aligns with the standard of care. A medical error, on the other hand, results from a medical intervention that departs from the standard of care.

The problem in medical malpractice is that errors of nature can be random occurrences even when a medical intervention complies with the standard of care. Lawsuits that result from such cases are often without merit. Eighty-five thousand lawsuits are filed per year, two-thirds of which fit this category. The odds for any doctor of being sued is 8.5 percent per year. Yet, behind each of those lawsuits is a medical expert who prepares a certificate of merit. Often, the medical expert is among the most respected in their specialty.

Why would a medical expert do so? Regardless of prestige, standing, professional credentials, or a self-proclamation as a guardian of the standards of care, there is one more reason—money.

I do not begrudge any of their reasons. Neither do I deny that negligence occurs, nor do I deny that the medical profession should be self-governing. What matters is that medical experts remain honest. However, for every medical expert that prepares a certificate of merit for a plaintiff attorney, whether there is merit or not, there is a medical expert hired by a defense attorney. At least one of them is lying.

They validate their existence from lawsuits and do so by using “preponderance of evidence” as defined in the law by lawyers. This standard corresponds to a 50 percent probability plus some vague value, usually a scintilla. As of now, this is the threshold that separates an error of nature from a medical error. In general, doctors are not so casual in decision-making.

This means that “more likely than not” a medical error is caused by a medical intervention that departs from the standard of care, even when it is an error of nature and there is no departure from the standard of care. How often is the mantra, “more likely than not,” repeated by these medical experts? This is what is validated in a certificate of merit prepared by them.

Statistical significance is different from preponderance of evidence. It is the likelihood that an unfortunate outcome and a medical intervention are related or not related by random chance. Preponderance of evidence is a standard in the law, whereas statistical significance is a standard in medicine.

By convention, and only by convention, that vague value in preponderance of evidence is a “scintilla.” At the very least, this burden of proof has a level of confidence of around 51 percent and a type-1 error of around 49 percent. Level of confidence is the odds of being right; type-1 error is the odds of being wrong.

“More likely than not” is nothing better than inference. However, inference is just enough to satisfy the medical expert who prepares the certificate of merit when you are sued—and you will be.

With statistical significance, the so-called “vague value” is 45 percent. This corresponds to a level of confidence of 95 percent and a type-1 error of 5 percent. This is concrete proof.

As a standard in medicine, it should be documented in medical records that there is a 95 percent confidence that the medical intervention upon which you embark is expected to have a successful outcome. Hence, statistical significance is self-governance, and it begins when each of us creates this documentation in medical records we prepare.

By contrast, preponderance of evidence is a legal concept that represents the lowest standard of evidence. This is what lawyers demand of medical experts.

We are doctors. We set our own standards. Medical experts, who are also doctors, are obligated to the standards of the medical profession, regardless of what the lawyers who retain them demand. Medical experts would be loath to defy the medical profession. For this reason, I urge all my colleagues to rethink preponderance of evidence in terms of statistical significance.

After such consideration, preponderance of evidence is no longer enough when a medical expert prepares a certificate of merit. There must be a statistically significant difference between the incident risk of a medical error resulting from a medical intervention and the background risk of an error of nature resulting from that same medical intervention for there to be a departure from the standard of care.

When we set this standard, there is nothing lawyers can do. They may litigate medical malpractice, but medical experts prepare the certificates of merit. Should one depart from a professional obligation, they are accountable to the medical profession. Lawyers need medical experts more than medical experts need lawyers. Only then is the medical profession truly self-governing.

Howard Smith is an obstetrics-gynecology physician.