Medical malpractice law is notoriously complex, with variations from state to state and legal standards that evolve over time. Physicians can face liability exposure in ways that aren’t always obvious from day-to-day clinical practice.
One doctrine that has expanded malpractice exposure in many states is the loss-of-chance doctrine. Under this legal theory, you may be held liable if proven negligence reduced a patient’s chance of a better outcome, even when it cannot be shown that the negligence was the sole cause of the patient’s injury. In some jurisdictions, loss-of-chance claims can arise from delayed diagnoses or delayed treatment even when a patient’s original prognosis was already poor.
One Sermo member defines medical malpractice suits as “civil litigation grounded in the concept that a harmed person can be ‘made whole’ by compensating them for their loss.” The loss-of-chance doctrine developed as a legal framework for addressing situations in which the alleged harm is a diminished prognosis rather than a discrete physical injury.
This is not just speculation that things may have been able to go better and it is also not suing for a future damage that might never occur.
Consider a lawsuit against a radiologist for not detecting a small early breast cancer. The plaintiff, whose tumor was over 2.2 cm and with three positive lymph nodes at the time of later diagnosis, is now suing not just for her damages for the more extensive treatment that she required than if she was diagnosed and treated while Stage I – she is also, despite being currently cancer-free, alleging a decreased chance to survive.
What puts this under the umbrella of being “made whole” is that the she is suing for a damage that has already accrued: losing a chance for full cure. In other words, insofar as being “made whole”, wholeness encompasses her prognosis.
By grasping how courts view this diminished potential, you can better protect your practice and your peace of mind. This article explores important points that you need to know as a practicing doctor.
This article reflects real conversations taking place within the Sermo physician community and is published for educational purposes only. It does not constitute legal or medical advice. The information provided is general in nature; laws governing medical malpractice, standard of care and liability vary significantly by jurisdiction. Physicians should contact a qualified legal representative for advice specific to their circumstances. Quotes from community members have been anonymized.
How common is delayed diagnosis in malpractice claims?
Delayed diagnosis malpractice is a fairly common type of medical malpractice claim. Diagnostic errors are the most common category of medical malpractice claim, accounting for 26.6% of paid claims in a study analyzing claims between 1999 and 2018. “Delay in diagnosis” was the second most common allegation type within that category, accounting for 24% of the claims.
Another study from 2024 underscored the severity of this issue, finding that 23% of patients transferred to an ICU or who died in the hospital had a missed or delayed diagnosis that contributed directly to their outcome.
As for office settings, nearly 45% of about 6,000 closed malpractice events alleged missed cancer diagnoses in a 2025 white paper report from the insurance company Coverys. Prostate, lung, breast and colorectal cancers were the most commonly named diseases in those claims. Internal medicine and family medicine physicians were the most frequently named specialists in those cases, accounting for 41% of the events and 45% of the indemnity paid.
What exactly is the loss of chance doctrine?
The loss-of-chance doctrine is commonly applied in delayed diagnosis cases. The doctrine allows a patient to sue for medical malpractice if a physician’s negligence reduced their likelihood of a better clinical outcome, even if their baseline chance of survival was already below 50%.
“The plaintiff making a loss of chance claim does not have to prove that they would have definitely done well if there had not been negligence in their care,” notes one physician on Sermo with medicolegal experience.
Courts in jurisdictions that have adopted the loss of chance doctrine ask whether the negligence diminished the patient’s chance of a better outcome, not whether the negligence caused death or ultimate injury. For example, the Massachusetts Supreme Court stated that if a physician’s breach of duty eliminated or diminished the patient’s chance of survival or of a better outcome, that physician had deprived the patient of “something of value.”
Where the loss of chance doctrine applies
As of a 2021 article published in Human Genetics and Genomics Advances, 29 U.S. states have adopted the loss of chance doctrine, giving plaintiffs a path to recover damages for a reduced likelihood of a better medical outcome. Meanwhile, 15 states have explicitly rejected the doctrine and six states have either deferred or not yet addressed the issue.
The following table details which doctrines apply in which jurisdictions:
| Doctrine status | Jurisdictions |
| Adopted | Arizona, Connecticut, Delaware, Hawaii, Illinois, Indiana, Iowa, Kansas, Louisiana, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nevada, New Jersey, New Mexico, New York, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Washington, West Virginia, Wisconsin, Wyoming, Utah |
| Rejected | Alabama, Alaska, Florida, Idaho, Kentucky, Maryland, Maine, Nebraska, New Hampshire, North Carolina, South Carolina, South Dakota, Tennessee, Texas, Vermont |
| Deferred or unaddressed | Arkansas, Colorado, Rhode Island, Virginia, California, Georgia |
Some states have prohibited or restricted the doctrine even after their courts initially adopted it. For instance, in South Dakota, lawmakers argued that the doctrine conflicted with the traditional requirement that a plaintiff prove the physician’s negligence directly caused the patient’s injury.
Even within adopting jurisdictions, the application varies significantly. Multi-state practitioners can be subject to different laws depending on where they treated the patient. Some states allow for full damages to be awarded once a specific loss of chance threshold is met. Other states use a “proportionality” approach, where damages are scaled to the percentage of the lost chance.
For example, “if a patient has a 30% chance of survival with a diagnosis but the diagnosis was missed and later diagnosed when there is a 10% chance of survival, then the patient theoretically is owed the 20% loss,” Brittnie Hayes, Esq., interim senior vice president of claims at The Doctors Company, tells Sermo.
One Sermo member finds the loss of chance doctrine sound. “If I understand correctly, the doctrine of missed opportunities rightly recognizes that medicine is probabilistic, not exact,” they write. “And this is positive in a world where doctor-patient litigation is increasingly escalating to conflict, sometimes with a compensation industry we even see advertised for.”
How is the loss of chance doctrine proven in court?
To prove loss of chance in court, a plaintiff must demonstrate through expert testimony that the physician deviated from the standard of care and that the deviation caused a measurable (often a “substantial”) reduction in their statistical probability of survival or recovery.
The meaning of the word “substantial” is open to interpretation. In Minnesota, a 20% reduction (from 60% to 40%) in an infant tumor case was held to be substantial. In Washington, a 14% reduction in a lung cancer case was accepted. Ultimately, this is case-specific and jury-dependent.
Expert testimony is central to these cases. “The expert must base their assessment on reliable data to establish what the expected patterns for the illness are, and must also go beyond bare statistics to show that the probability of recovery of that individual plaintiff fell within the statistical range quoted for patients with that condition,” a physician with medicolegal experience writes on Sermo.
“The reason why such claims are hard to prove is that there is usually uncertainty about them,” says Benson Varghese, founder and managing partner of Varghese Summersett. “The plaintiff’s attorney tries to prove that had the treatment been provided earlier, the chances of recovery would have been higher. Thus, such cases tend to be very much dependent on medical evidence presented by the parties involved.”
How can physicians protect themselves against delayed diagnosis liability?
As a physician you can reduce delayed diagnosis liability with clear documentation and communication with patients. “Physicians can reduce their risk by utilizing better tracking systems for test results (such as leveraging EMR tracking alerts), better communication for hand-offs (multiple practitioners involved leads to a greater need for communication), and increased communication to the patient on return precautions,” Hayes says.
Use detailed documentation
Documentation errors factor into about 20% of malpractice cases, according to a 2024 report from Candello, a database of U.S. medical professional liability (MPL) claims. A note that says “Rule out PE, ACS, dissection” shows your clinical reasoning, even if the eventual diagnosis was different. A note that merely lists the final chosen diagnosis on the other hand, does not.
“Sometimes the problem is a missed blood test result, a referral that was not handled, poor communication, or symptoms that were not followed up on,” McCready confirms. Build a habit of using systems that track outstanding labs, imaging, biopsies and consult notes through to closure.
Qualify your notes with a complete picture of the diagnostic process, one Sermo member urges. “Proper documentation provides a clear insight of what tests and images are remaining for a proper diagnosis,” they write.
Communicate clearly with patients
One way to reduce your risk of liability related to loss of chance is “increased communication to the patient on return precautions,” Hayes notes. A documented conversation noting that the patient understood the working diagnosis was provisional, that further evaluation was warranted or that they should return if symptoms persisted can defend you against a plaintiff claiming, “I was reassured I was fine.”
Use shared decision-making and informed consent properly.Whena patient declines a recommended biopsy, refuses a follow-up or chooses to defer testing, it changes the liability picture. However, this defense only exists if that specific conversation was thoroughly documented.
When to involve risk management or legal counsel
It’s important to know when to escalate a concern. You should involve your risk management team or legal counsel in the following scenarios:
- When you become aware of a significant missed or delayed diagnosis, particularly if patient harm may have occurred
- As soon as a patient or family member raises a verbal or written concern about a prior visit or a missed finding
- If you receive a request for medical records directly from a plaintiff’s attorney
- If you are notified of a potential claim or receive a formal Notice of Intent to Sue
- If a colleague’s case raises serious questions about your own diagnostic process or shared patient care
As a general rule, bring in your malpractice carrier and risk management team early rather than hoping the issue will resolve quietly on its own. The cost of an early consultation is small, but the cost of a late one is sometimes the difference between a manageable case and an unmanageable one. For more background on malpractice insurance and what triggers premium changes, consult Sermo’s guide to malpractice insurance costs.
Mitigate your risk
Delayed diagnosis remains one of the most common categories in medical malpractice litigation, and the loss of chance doctrine has expanded physician exposure in the majority of U.S. states. While traditional malpractice suits ask, “did the negligence cause the bad outcome?” the loss-of-chance doctrine asks, “did the negligence diminish the chance of a better outcome?”
In these scenarios, your defense depends on the quality of your documentation and the reliability of your follow-up systems. Ideally, you’ll document your reasoning clearly and close the loop on all diagnostic results, even if it feels like extra work. “Nobody likes to document, but we need to remember that it’s part of our jobs, unfortunately,” a Sermo member writes.
You can join peer discussions to dive deeper into medicolegal topics. On Sermo, physicians discuss legal scenarios, share the documentation habits that hold up under scrutiny and dissect the cases that did not. Access the medical community where you can share insights, solve challenging patient cases and learn how to better protect your practice alongside colleagues worldwide.
This article has been medically reviewed by a member of the Sermo physician community.
