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What Are the 4 D’s of Medical Negligence?

Written by Berkowitz

Surgeons in operating room Connecticut hospital

The “4 D’s” of medical negligence is a shorthand term that refers to the four legal elements you have to prove in order to win a medical malpractice lawsuit: (i) duty (ii) deviation from the standard of care (iii) damages, and (iv) direct causation.

There is nothing unusual about medical negligence – medical errors cause around 250,000 deaths per year which, according to the American Medical Association itself, represents the nation’s third-leading cause of death. Unfortunately, however, defendants still win more than half of all medical malpractice claims that go to court (keep in mind that most medical malpractice claims are resolved outside of court).

Proving Your Case

The legal system applies very specific rules concerning how you go about proving a medical malpractice claim. Among the applicable concepts, the burden of proof and the standard of review are critical.

The Burden of Proof

The burden of proof refers to which party has the responsibility of proving the case. If you file a medical malpractice lawsuit against a doctor, for example, is it your responsibility to prove that the doctor was negligent, or is it the doctor’s responsibility to prove that he was not negligent? The answer is that it is your responsibility to prove that the doctor was negligent. If neither side presents any credible evidence, the doctor wins.

The Standard of Review

The “standard of review” refers to the amount of evidence you need to prove your case. In a criminal prosecution, for example, the standard is “beyond a reasonable doubt.” The standard of review in a civil action such as a medical malpractice lawsuit is a “preponderance of the evidence,” which is a far easier standard to meet.

“Preponderance of the evidence” means that, when all evidence has been presented by both sides, the evidence in favor of medical malpractice at least slightly outweighs the evidence against it – with a 51 percent likelihood, for example. You must prove that all four elements of medical malpractice have been met, by a preponderance of the evidence, in order to win. Failing to prove any one of them will doom your case.

The Good Faith Certificate and the Opinion Letter

In order to prevent frivolous medical malpractice lawsuits, the state of Connecticut requires that anyone filing a medical malpractice lawsuit submit:

  • a “certificate of good faith” in which your lawyer states that he has investigated your claim and has concluded “in good faith” (honestly) that medical malpractice occurred; and
  • an opinion letter from a “similar health care provider” stating that, in his opinion, medical malpractice occurred in your case.

In order to persuade a “similar health care provider” of the merits of your case, you are going to need to perform an investigation that establishes the likelihood that all of the “4 D’s” are likely to be present in the fact pattern that represents your case.

The Four D’s: An Explanation

Following is a more detailed explanation of the “four D’s” mentioned above:


“Duty” refers to the health care provider’s duty of care with respect to your treatment. Due to his extensive training, a doctor is held to a professional standard of care – a much higher standard of care than an ordinary citizen is subject to. For example, a witness to a car accident who renders first aid will not likely be held to a professional standard of care.

The specifics of the duty of care varies even among doctors. If you suffer a heart ailment, for example, a general practitioner’s duty of care will be much more lenient than the duty of care applied to a cardiologist. Nevertheless, even your family doctor is expected to know when the demands of treating your condition exceed his level of expertise and that he should, therefore, refer you to a specialist.

Deviation from the Standard of Care

Most medical malpractice claims revolve around this element, because it is typically the most difficult element to prove and because the standard is ambiguous enough for experts to disagree. A great many deviations from the standard of care fall within one of the following categories:

  • Misdiagnosis;
  • Delayed diagnosis;
  • Medication errors;
  • Anesthesia errors;
  • Birth injuries;
  • Unnecessary medical treatment; or
  • Surgical errors.

Expert Witnesses

Proving deviation from the standard of care typically requires the testimony of expert medical witnesses.  Expert medical witnesses are trained in medicine; they are almost always licensed MDs; and they are typically full-time professional witnesses who have retired from the practice of medicine.

Although these witnesses require payment for their testimony, they are still legally bound to provide their honest professional opinion. Although, if you call a paid professional witness, you can be sure that the opposing party’s lawyer will bring this fact to the court’s attention. However, the use of paid professional witnesses is routine in medical malpractice cases.


Damages represent the amount that you lost or suffered. Damages might include, for example, your medical bills, lost earnings while you were in the hospital or at home recovering, lifetime lost earnings if permanent medical issues prevent you from returning to your previous occupation, child care expenses, the physical pain and mental anguish that you suffered, lifestyle problems due to permanent impairments, and other losses.

You must prove every dime of your damages. If you are claiming $1,000,006 in damages, for example, then you must prove $1,000,006. When it comes to ambiguous elements of damages such as pain and suffering, certain formulas are often used, such as a multiple of your medical expenses.

Evidence of Damages

Evidence of damages might include, among other items:

  • Medical records;
  • Prescription records;
  • Statements from an expert witness (concerning the degree of physical pain your condition typically causes, for example);
  • Your own testimony; and
  • Medical bills.

It can be particularly tricky to calculate your total damages if you are totally disabled and will require continuing medical treatment for decades to come. It is important that you get the amount right, preferably with the help of a skilled and experienced medical malpractice lawyer. Because if you run out of money, there will be no way for you to come back to court or the negotiating table to ask for more money.

Direct Cause

Causation is the second most litigated legal element of medical malpractice. No matter how negligent your healthcare provider might have been, you have no valid medical malpractice claim unless you can prove, by a preponderance of the evidence, that the damages you are claiming were actually caused by the doctor’s negligence.

The causation must be direct. If your doctor failed to diagnose your cancer and as a result you joined a football league and broke your arm, you cannot claim damages against your healthcare provider for your broken arm by claiming that you never would have joined the football league in the first place if you had known you had cancer. If the doctor who treated your broken arm failed to set it properly, on the other hand, you might have a valid claim.

Disputing the “4 D’s”: Possible Defenses the Defendant Might Assert

The number of specific defenses that a healthcare provider might assert are just about as numerous as the types of medical malpractice claims that might be asserted against him, and they are heavily dependent on the precise facts of each individual claim. Nevertheless, medical malpractice defenses tend to cluster around certain commonly used categories of defenses, such as:

Duty-Based Defenses

Suppose your doctor was an off-duty bystander to a car accident that you were involved in and rushed in to render first aid. If you sue him for failing to meet the standard of care that applies to a doctor with his level of training, he might assert the Connecticut Good Samaritan Law, which would likely protect him unless his error was so serious that even someone untrained in medicine should have known not to commit it.

Likewise, if you sued a doctor who provided general advice on the internet because you followed his advice and your condition worsened, he might assert that you have no valid claim because duty arises from a doctor-patient relationship and no doctor-patient relationship was established in this case.

Defending against a Claim of Deviation from the Standard of Care

If you produce expert medical witnesses who assert that the defendant deviated from the applicable standard of care, the defendant might produce expert medical witnesses of his own who assert the exact opposite. In this case it will be up to the jury to decide whose expert testimony they find the most convincing.

This type of defense is likely to become scientifically complex, as the minute details of treatment are scoured and examined for their propriety. Ultimately, the decision is subjective in most cases – what would a “reasonable” physician have done under similar circumstances?

Disputing Your Claim of Damages

This type of defense does not always involve the defendant denying liability altogether, but simply trying to reduce the amount of liability. These defenses tend to come in two varieties:

  • The defendant directly disputes your claim of damages. Your child care expenses were not as much as you are claiming, for example, or your occupational disability as a result of the malpractice is not as severe as you say it is.
  • The defendant takes advantage of the ambiguous nature of many elements of a medical malpractice damages claim. How do you put a dollar value on pain and suffering, for example? The defendant might claim that your demand is simply too high. Alternatively, the defendant might dispute your estimate of future medical expenses, which are inherently difficult to accurately calculate.

Remember: To win the case, all the defendant has to do is to deny you a preponderance of evidence in proving any one of the “4Ds.” Even at the negotiating table, the defendant might refuse to yield if he thinks he can win in court. Your case is going to need to be airtight to win, which means you are likely to need an experienced malpractice lawyer to help you prepare your case.

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If you believe that you may be a victim of medical malpractice, call Berkowitz Hanna today  or simply contact us online for a free initial consultation.