Loss of Chance Doctrine in Medical Malpractice

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 What Is Loss of Chance in Medical Malpractice?

“Loss of Chance” is a legal doctrine related to medical malpractice lawsuits. It applies when a medical professional’s negligence (for example, a misdiagnosis or delayed diagnosis) does not directly cause a patient’s injury or condition, but instead deprives them of a chance of a better outcome or survival.

For instance, let’s say a doctor misdiagnoses a patient’s early-stage cancer. Say the patient eventually passes away from this cancer. It may not be provable that the misdiagnosis directly caused the patient’s death (as they might have died even with correct and early treatment). However, the misdiagnosis clearly deprived the patient of a better chance at survival or a more favorable outcome.

In such scenarios, the doctrine of “Loss of Chance” allows for recovery of damages based on the percentage of the lost chance. The patients (or their families) do not have to prove that the medical professional’s negligence directly resulted in the harm but merely that it decreased their chances of a better outcome.

The acceptance of this doctrine varies depending on jurisdiction. Some courts accept it, while others require plaintiffs to prove that the medical professional’s negligence was more likely than not the cause of the injury. This standard is often referred to as the “more probable than not” or “preponderance of the evidence” standard.

Elements to Prove Loss of Chance

To succeed in a “loss of chance” claim in a medical malpractice lawsuit, a plaintiff typically needs to prove the following elements:


The plaintiff must establish that the healthcare provider owed a duty to the patient. In a medical malpractice negligence context, this duty often arises from the physician-patient relationship.

Breach of Duty

The plaintiff must show that the healthcare provider breached this duty. Usually, this is determined by the “medical standard of care.” It is defined as the level at which the average, prudent provider in a given community would manage a patient’s care under the same or similar circumstances. In other words, if the healthcare provider’s care falls below the medical standard of care, they have breached their duty.


The plaintiff must demonstrate that the healthcare provider’s breach of duty resulted in the loss of a chance for a better outcome. This is where the “loss of chance” doctrine deviates from traditional negligence cases. Instead of proving that the negligence more likely than not resulted in the patient’s injury or condition, under the “loss of chance” doctrine, the plaintiff must show that the healthcare provider’s negligence reduced the patient’s chance of a better outcome.


The plaintiff must demonstrate that they suffered damages as a result of the loss of chance. These damages are often measured as the value of the lost chance. For example, assume that the patient had a 40% chance of survival and had they received appropriate care, and that chance was reduced to 0% because of the healthcare provider’s negligence. In that case, the damages would be based on the loss of that 40% chance.

Here’s another example:

Let’s say a patient visits a physician complaining of persistent headaches. The physician dismisses it as stress-related without ordering any further tests. Later, it was discovered that the patient had a treatable brain tumor. However, due to the delay in diagnosis, the tumor advanced to a stage where treatment options are limited and the prognosis is poor.

Now, let’s assume that if the tumor had been diagnosed and treated earlier, the patient would have had a 70% chance of full recovery. However, because of the delayed diagnosis, the patient’s chance of full recovery dropped to 20%.

In this scenario, say the patient’s lost chance is 50% (70% – 20%). If a court determines that the total damages associated with the full impact of the illness, considering factors such as medical costs, pain and suffering, lost wages, etc., amount to $2,000,000. In that case, the loss of chance damages awarded would be $1,000,000 (50% of $2,000,000), assuming the court follows the approach of awarding damages proportional to the lost chance.

Quantification of Loss

Unlike traditional negligence claims where the plaintiff must prove that the harm would not have occurred but for the defendant’s actions, in a loss of chance case, the plaintiff must quantify the lost chance. That is, they need to establish the difference between the patient’s chance of a better outcome before and after the alleged negligent act.

Bear in mind that the specific requirements for a “loss of chance” claim can vary between different jurisdictions. In some jurisdictions, the doctrine might not be recognized, or it might be recognized but applied differently.

How Are Damages Awards Calculated in a Loss of Chance Case?

Calculating damages in a loss of chance case can be quite complex and often requires expert testimony, particularly from medical professionals and possibly economists or actuaries. The calculation generally aims to quantify the value of the lost opportunity for a better outcome.

First, the percentage of the lost chance must be determined. Typically, this is done by comparing the patient’s chance of survival or better outcome before and after the alleged negligence. This requires expert medical testimony to establish the likely outcomes in each scenario.

For example, assume that a patient had an 80% chance of survival with a timely cancer diagnosis and treatment. Because of a negligent delay in diagnosis and treatment, the chance of survival dropped to 40%, the lost chance would be 40% (80% – 40%).

Next, this percentage is applied to the total potential damages in the case. If a jury determines that the total damages (considering aspects like loss of life, pain and suffering, loss of earnings, etc.) are $1,000,000, then in this example, the damages awarded for the lost chance would be $400,000 (40% of $1,000,000).

This approach of calculating damages attempts to compensate the plaintiff for what they lost due to the healthcare provider’s negligence—the chance for a better outcome. But it’s important to remember that the legal standards and methods for calculating damages can vary significantly by jurisdiction. Some courts may not recognize loss of chance damages or may apply different standards for determining damages.

Do You Need an Attorney Experienced With Medical Malpractice?

When dealing with complex legal issues such as medical malpractice and particularly when exploring “loss of chance” claims, it is highly recommended to work with an attorney with substantial experience in medical malpractice lawsuits.

Medical malpractice law is a complex field. It involves understanding medical terminology and procedures, complex legal principles, and the ability to navigate through an intricate healthcare system. An experienced personal injury lawyer can effectively navigate these challenges and help you understand your rights and legal options.

If you or a loved one has been a victim of medical malpractice, it’s crucial that you secure the right legal representation. LegalMatch can help you find the right lawyer for your case. Through LegalMatch, you can quickly find pre-screened lawyers in your local area who are ready to help. Simply present your case, and LegalMatch will connect you with a medical malpractice attorney who matches your needs.

Remember, with a subject as serious as medical malpractice, you need someone on your side who knows the law, understands your situation, and can effectively fight for your rights. Don’t delay. Find the right legal representation through LegalMatch today.

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