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Loss of Chance Doctrine in NY: Calculating Damages for Delayed Diagnosis

Excerpt: When a physician's negligence reduces your chance of survival — even if your prognosis was already poor — New York's loss of chance doctrine allows you to recover damages. This guide explains how it works.

Table of Contents

1. The Problem: When the Patient Was Already Sick
2. What Is the Loss of Chance Doctrine?
3. New York's Adoption of the Doctrine
4. When Loss of Chance Applies
5. The "Substantial Possibility" Standard
6. How Damages Are Calculated
7. Expert Testimony: The Biostatistician
8. Case Examples: Cancer, Heart Attack, Stroke
9. Loss of Chance vs. Traditional Causation
10. Limitations of the Doctrine
11. Statute of Limitations
12. Frequently Asked Questions

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The Problem: When the Patient Was Already Sick

In a traditional medical malpractice case, the plaintiff must prove that the physician's negligence caused the injury. This requires showing that "but for" the negligence, the injury would not have occurred — or that the negligence was a substantial factor in causing the injury.

But what about the patient who was already seriously ill — whose chance of survival was less than 50% even with proper care? Under traditional causation rules, if the patient's chance of survival was already below 50%, the physician could argue: "The patient was probably going to die anyway, so my negligence didn't cause the death."

This is the "lost chance" problem: the physician's negligence reduced the patient's chance of survival, but the patient's chance was already poor. Under traditional rules, the patient (or their family) might recover nothing — even though the physician clearly committed malpractice.

New York's loss of chance doctrine addresses this injustice.

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What Is the Loss of Chance Doctrine?

The loss of chance doctrine allows a plaintiff to recover damages when the physician's negligence reduced the patient's chance of survival or better outcome — even if:

1. The patient's chance of survival was already less than 50%
2. The patient may have died (or had a bad outcome) even with proper care

Under this doctrine, the plaintiff does not need to prove that the physician's negligence caused the bad outcome. Instead, the plaintiff proves that the negligence reduced the chance of a better outcome.

The damages are then calculated proportionally to the lost chance.

Example

• A patient had a 40% chance of survival with timely diagnosis
• The physician's 6-month delay reduced the chance to 15%
• The patient died
• Under the loss of chance doctrine, the plaintiff recovers damages proportional to the 25% reduction in survival probability (40% - 15% = 25%)

New York's Adoption of the Doctrine

New York adopted the loss of chance doctrine in the landmark case Flanigan v. Grenier (1986). The New York Court of Appeals held that a plaintiff could recover damages for the lost chance of survival even when the patient's prognosis was already poor.

Since Flanigan, the doctrine has been refined through subsequent case law, including:

• Parker v. Pratissima (2006) — Addressing the standard for proving loss of chance
• Matter of New York City Asbestos Litigation — Applying loss of chance in toxic tort cases

The doctrine is now a well-established principle in New York medical malpractice law, particularly in delayed diagnosis and failure to diagnose cases.

When Loss of Chance Applies

The loss of chance doctrine most commonly applies in:

1. Delayed Cancer Diagnosis

When a physician delays diagnosis of cancer, the patient's chance of survival may decrease. For example:

• At the time of the missed diagnosis — 70% chance of 5-year survival
• At the time of actual diagnosis (6 months later) — 35% chance
• The lost chance is 35 percentage points

2. Delayed Heart Attack Diagnosis

When an ER delays heart attack diagnosis, the patient may lose heart muscle that could have been saved. The loss of chance doctrine can quantify the reduction in cardiac function or survival probability.

3. Delayed Stroke Diagnosis

When a stroke diagnosis is delayed, the patient may suffer brain damage that could have been prevented with tPA. The loss of chance doctrine can quantify the reduction in functional outcome.

4. Delayed Sepsis Diagnosis

When sepsis treatment is delayed, the patient's chance of survival decreases by approximately 7.6% per hour. The loss of chance doctrine can quantify this reduction.

The "Substantial Possibility" Standard

New York courts require the plaintiff to prove that the physician's negligence caused a "substantial possibility" of a better outcome. This is a lower standard than the traditional "more likely than not" (greater than 50%) standard.

What Constitutes a "Substantial Possibility"

The courts have not defined an exact percentage, but generally:

• A 14% or greater reduction in chance of survival is likely sufficient
• A very small reduction (e.g., 1-2%) may not meet the standard
• The reduction must be supported by expert testimony and medical evidence

Expert Testimony

The plaintiff must present expert testimony — typically from a biostatistician or epidemiologist — who calculates:

1. The patient's chance of survival/better outcome at the time of the negligence
2. The patient's chance of survival/better outcome at the time of actual diagnosis
3. The difference — which represents the lost chance

How Damages Are Calculated

Step 1: Calculate Total Damages

First, the jury calculates the total damages — the full value of the injury or death, including:

• Medical expenses
• Lost wages
• Pain and suffering
• Loss of future earnings
• Loss of consortium (for spouses)
• Wrongful death damages (if the patient died)

Step 2: Determine the Lost Chance

The jury determines the percentage of lost chance — the reduction in survival probability caused by the negligence.

Step 3: Apply the Percentage

The total damages are multiplied by the lost chance percentage.

Example

• Total damages: $10,000,000
• Chance of survival at time of negligence: 60%
• Chance of survival at time of diagnosis: 30%
• Lost chance: 30 percentage points
• Recovery: $10,000,000 × 30% = $3,000,000

Important Note

New York does not require the jury to mechanically multiply damages by the percentage. The jury may consider the lost chance as a factor in determining the appropriate award.

Expert Testimony: The Biostatistician

The biostatistician or epidemiologist is a critical expert in loss of chance cases. This expert:

1. Reviews the medical literature on survival rates for the specific condition
2. Analyzes the patient's specific characteristics (age, stage, comorbidities)
3. Calculates the probability of survival at the time of negligence
4. Calculates the probability of survival at the time of actual diagnosis
5. Testifies to the reduction in probability

Survival Data Sources

• SEER (Surveillance, Epidemiology, and End Results) — For cancer survival data
• Medical literature — Peer-reviewed studies on survival rates
• Clinical guidelines — Treatment protocols and expected outcomes

Case Examples

Cancer Delayed Diagnosis

• A 55-year-old woman's breast cancer is missed on mammography
• At the time of the missed diagnosis (Stage I), 5-year survival was 99%
• 18 months later (Stage III), 5-year survival is 57%
• Lost chance: 42 percentage points

Heart Attack Delayed Diagnosis

• A 60-year-old man's heart attack is missed in the ER
• With prompt treatment (within 1 hour), chance of full recovery: 85%
• With 4-hour delay, chance of full recovery: 50%
• Lost chance: 35 percentage points

Stroke Delayed Diagnosis

• A 70-year-old woman's stroke is missed for 6 hours
• With tPA within 1 hour, chance of good outcome: 60%
• After 6-hour delay, chance of good outcome: 20%
• Lost chance: 40 percentage points

Loss of Chance vs. Traditional Causation

| Factor | Traditional Causation | Loss of Chance | |--------|---------------------|----------------| | Standard | "More likely than not" (>50%) | "Substantial possibility" | | What's proven | Negligence caused the injury | Negligence reduced chance of better outcome | | Damages | Full damages | Proportional to lost chance | | When it applies | When negligence was the primary cause | When negligence reduced chance of survival | | Key expert | Treating physician | Biostatistician/epidemiologist |

Limitations of the Doctrine

Not Applicable in All Cases

The loss of chance doctrine does not apply when:

• The patient's chance of survival was already zero — No chance to lose
• The negligence did not reduce the chance of survival — The outcome would have been the same regardless
• The patient cannot prove the reduction in chance with expert testimony

The "Substantial Possibility" Requirement

The plaintiff must prove a substantial reduction in chance. A very small reduction may not meet the standard.

Jury Discretion

New York juries have discretion in how they apply the loss of chance percentage. They are not required to mechanically multiply — they may consider the lost chance as one factor.

Statute of Limitations

Under CPLR 214-a, the statute of limitations is 2.5 years from the date of the malpractice. Under Lavern's Law, the clock may start when the patient discovered the malpractice — particularly important in delayed cancer diagnosis cases.

Frequently Asked Questions

What is the loss of chance doctrine?

The loss of chance doctrine allows a plaintiff to recover damages when a physician's negligence reduced the patient's chance of survival — even if the patient's prognosis was already poor. Damages are proportional to the lost chance.

When does loss of chance apply in New York?

The doctrine most commonly applies in delayed diagnosis cases — particularly delayed cancer diagnosis, delayed heart attack diagnosis, delayed stroke diagnosis, and delayed sepsis diagnosis.

How are damages calculated under loss of chance?

The jury calculates total damages, determines the percentage of lost chance (reduction in survival probability), and may apply that percentage to the total damages. However, juries have discretion in how they apply the percentage.

What is the "substantial possibility" standard?

New York requires the plaintiff to prove that the negligence caused a "substantial possibility" of a better outcome. This is a lower standard than "more likely than not" (greater than 50%), but requires expert testimony to quantify the reduction.

Do I need a biostatistician as an expert?

In most loss of chance cases, yes. A biostatistician or epidemiologist calculates the patient's chance of survival at the time of negligence and at the time of actual diagnosis, and testifies to the reduction in probability.

How long do I have to file a claim?

Under CPLR 214-a, the deadline is generally 2.5 years from the date of the malpractice. Lavern's Law may extend this for cancer cases.

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If you or a loved one has been affected by medical negligence that reduced your chance of survival in New York, contact MDLaw Firm at 347-524-5777 for a free consultation.

This article is for informational purposes only and does not constitute legal advice. Prior results do not guarantee a similar outcome. No attorney-client relationship is created by reading this article or contacting MDLaw Firm.