Other Patient: DeMizio v. JHH 4

The Baltimore Medical Malpractice Lawyer Blog discusses an unreported opinion filed on May 8, 2026, in which the Appellate Court of Maryland ruled on a medical malpractice dispute. The case was Deidre DeMizio, et al. v. Johns Hopkins Health System Corp., et al. (No. 2412, September Term, 2023). It involved a wrongful death lawsuit. The plaintiffs asserted the case against a network of medical entities and doctors. They claimed the defendants failed to timely diagnose and treat a patient’s cardiac amyloidosis. This failure was prior to his sudden cardiac arrest death on December 15, 2017. Following a defense verdict delivered by a Montgomery County jury, the plaintiffs appealed several trial rulings. This is Part 4 of a Blog series on this case. It discusses the relevance in a medical malpractice case of an other patient’s experience with the drug treatment at issue.

In previous Part 1, I covered the trial court’s refusal to reopen discovery. Then Part 2 involved the limits placed on unapproved drug testimony under Daubert-Rochkind. Part 3 discussed the exclusion of post-dated medical literature.

Factual Background on Other Patient Evidence in Medical Malpractice Case

The multiple week trial progressed in the circuit court. A key element of the plaintiffs’ causation and damages strategy hinged on proving that if the decedent had been correctly diagnosed with cardiac amyloidosis during his lifetime, his condition could have been stabilized. To demonstrate this concept in the medical malpractice case, the plaintiffs sought to introduce the live testimony of a fact witness that had been an other patient who had taken the same drug treatment.

In this medical malpractice case, the other patient was an independent third party. He had no personal, familial, or professional relationship with the decedent. Nor did he possess any firsthand knowledge regarding the specific medical care, evaluations, or consultations provided by the defendant doctors. The other patient had also been diagnosed with cardiac amyloidosis.

According to the plaintiffs’ proffer, the other patient was prepared to testify that following his diagnosis, he successfully obtained the medication tafamidis through an experimental compassionate use program. He would testify that the drug effectively arrested the progression of his disease, stabilized his cardiac function, and significantly extended his life.

However, the timeline of the other patient’s medical journey differed from the decedent’s. Medical providers did not diagnose the other patient with cardiac amyloidosis until 2018. This was months after the decedent had already passed away. It was outside the February 2015 to December 2017 treatment window that formed the baseline of the lawsuit. The defendants objected to the other patient taking the stand. They argued that his anecdotal medical history was legally irrelevant and structurally prejudicial. The trial judge sustained the objection and barred the other patient from testifying int he medical malpractice trial. The plaintiffs appealed.

Parties’ Arguments

On appeal, the plaintiffs contended that the trial court committed a reversible error and abused its discretion by keeping the other patient from testifying. They argued that the other patient was a fact witness whose testimony proved the element of proximate causation. Specifically, they asserted that the other patient’s real-world survival story offered tangible, living proof to the jury that cardiac amyloidosis was not an automatic, immediate death sentence between 2015 and 2017.

By showing that another individual survived the exact same disease using a specific medical pathway, the plaintiffs believed they could demonstrate a “reasonable probability” that the decedent would have survived as well had he been properly diagnosed. The plaintiffs maintained that any differences between the other patient’s medical condition and the decedent’s went to the weight of the evidence, which the jury should evaluate, rather than its admissibility.

The defendants counter-argued that the trial court’s decision was a textbook application of Maryland Rules 5-401 and 5-402 governing legal relevance. They emphasized that in a medical malpractice action, a plaintiff cannot establish the standard of care or proximate causation by introducing the isolated, anecdotal experiences of a single, unrelated patient.

The defendants pointed out that the other patient’s diagnosis occurred in 2018. This meant his access to experimental protocols post-dated the decedent’s lifetime. It could shed no light on what treatments were widely accessible or standard between 2015 and 2017. They argued that allowing an unrelated patient to testify about his personal medical success would invite the jury to engage in speculation, drawing an unscientific, emotional equivalence between two entirely distinct human bodies and clinical timelines.

Court’s Ruling

The Appellate Court of Maryland looked at the trial judge’s exclusion of the other patient under a de novo standard for the threshold determination of legal relevance, and an abuse of discretion standard regarding the trial court’s overall management of witness evidence. The appellate court affirmed the trial court’s ruling, holding that the other patient’s proposed testimony was irrelevant as a matter of law.

Citing Maryland Rules 5-401 and 5-402, the court noted that evidence is only admissible if it has a logical tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence.

Two Flaws

The court split its medical malpractice analysis of the other patient’s testimony into two fatal flaws:

First, the court discussed the complete absence of factual overlap. The other patient had no connection to the case, no knowledge of the decedent, and no insight into the actions of the defendant physicians. His testimony amounted to an isolated, personal case study of an entirely different patient with a distinct genetic makeup, age, medical history, and clinical progression.

Second, the court focused on the timeline gap. Because the other was not diagnosed until 2018, his inclusion in an experimental compassionate use program occurred after the decedent had already died. The court noted that availability of an experimental protocol in 2018 does not prove that a community physician in 2015 or 2016 could have legally or practically secured that same treatment for a patient.

The appellate court concluded that the other patient’s personal clinical outcome had absolutely no legal relevance. It did not show whether the defendants breached the standard of care or caused the decedent’s death. Because the testimony could not make any fact of consequence more or less probable, it was properly barred.

Commentary by Baltimore Medical Malpractice Lawyer Mark Kopec on the Relevance of Other Patient’s Experience

The Appellate Court of Maryland’s decision to affirm the exclusion of the other patient’s testimony was correct. A single patient’s positive response to a drug or protocol proves nothing. It does not show how a different patient will react to that same drug. Two patients diagnosed with the exact same broad disease category may have vastly different situations. Different comorbidities, genetic expressions, structural heart damage, and tolerance levels. Allowing the other patient’s evidence would unfairly shift the burden onto the defense. They would have to practically litigate the other patient’s medical chart. They would try to prove why his body was different from the decedent’s. This would result in a potentially confusing, time-wasting “mini-trial” within a trial.

If the court allowed this testimony, defendants would conversely be incentivized to search the country for patients who took the drug and died. They would present their own parade of tragic anecdotes. Broad, peer-reviewed epidemiological data, and clinical trials may be relevant, but not individual anecdotes.

In addition, the other patient did not enter the medical system as an amyloidosis patient until 2018. Thus, his narrative belongs to a different era of medical availability. Things can change fast in the evolution of experimental drug pipelines. A drug may be highly restricted or completely not available in one year. Then it might suddenly open up through an expanded access protocol two years later. Permitting the jury in this medical malpractice case to listen to the other patient’s timing would could confuse them with a different compassionate use framework.

Series Conclusion

With this fourth holding affirmed, the Appellate Court of Maryland then completely upheld the defense verdict in DeMizio v. Johns Hopkins Health System Corp. Taken as a whole, this four-part opinion serves as a reminder for Maryland trial lawyers. Success in complex medical malpractice actions requires compliance with scheduling orders, a foundation for expert opinions, a literature focus on the exact dates of treatment, and also a rejection of anecdotal evidence.

You can read other Blog posts on Evidence issues in other cases.

Mark Kopec is a top-rated Baltimore medical malpractice lawyer. Contact us at 800-604-0704 to speak directly with Attorney Kopec in a free consultation. The Kopec Law Firm is in Baltimore and helps clients throughout Maryland and Washington, D.C. Thank you for reading the Baltimore Medical Malpractice Lawyer Blog.