Lab Error and Blood Test Malpractice in New York

How Lab Errors Happen

Laboratory testing involves a multi-step process — and errors can occur at any stage:

• Pre-analytical errors (before testing): Occur during sample collection, labeling, transport, or storage. Examples: drawing blood from the wrong patient, mislabeling samples, using the wrong collection tube, improper storage temperature, or delayed transport.
• Analytical errors (during testing): Occur during the actual analysis of the sample. Examples: equipment malfunction, reagent errors, calibration problems, contamination, or technician error in performing the test.
• Post-analytical errors (after testing): Occur during result reporting and communication. Examples: transcription errors (entering wrong values), reporting results to the wrong patient, delayed reporting, or failure to communicate critical results to the treating physician.
• Interpretation errors: The pathologist or laboratory director misinterprets the test results — particularly in pathology (biopsy) and cytology (Pap smear) specimens. [Link to: /misdiagnosis/pathology-biopsy-errors]

Common Types of Lab Errors

Specific types of lab errors that can cause patient harm include:

• Patient misidentification: Drawing blood or collecting a biopsy from the wrong patient, or applying the wrong label to a sample.
• Sample mix-up: Swapping samples between patients — leading to results being reported to the wrong patient.
• Mislabeled samples: Missing, incomplete, or incorrect labels.
• Improper collection: Using the wrong tube, insufficient sample volume, or improper collection technique.
• Improper storage or transport: Samples that are not kept at the right temperature, not transported promptly, or exposed to conditions that affect the results.
• Equipment malfunction: Analyzers that are not calibrated, maintained, or functioning properly.
• Reagent errors: Using expired, contaminated, or incorrect reagents.
• Contamination: Samples contaminated with other substances or organisms.
• Transcription errors: Entering incorrect values or results into the laboratory information system.
• False negatives: The test fails to detect a condition that is actually present — delaying diagnosis of cancer, infection, or other serious conditions.
• False positives: The test detects a condition that is not actually present — leading to unnecessary procedures, anxiety, and treatment.
• Failure to communicate critical results: Critical or abnormal results that are not communicated to the treating physician in a timely manner. [Link to: /delayed-diagnosis-lawyer/failure-to-follow-up]
• Pap smear misinterpretation: The cytotechnologist or pathologist misinterprets the Pap smear — missing abnormal cells or over-calling benign changes. [Link to: /misdiagnosis/pap-smear]
• Biopsy misinterpretation: The pathologist misreads the biopsy — missing cancer or diagnosing cancer that is not present. [Link to: /misdiagnosis/pathology-biopsy-errors]

The Chain of Custody in Laboratory Testing

Accurate laboratory testing depends on a proper chain of custody — the documented trail of who handled the sample at each stage, from collection to reporting. The standard of care requires:

1. Proper patient identification at the time of collection — using two identifiers (name and date of birth) and verifying against the order.

2. Proper labeling of the sample at the bedside (or point of collection) — not later at the lab.

3. Proper collection technique — using the correct tube, container, and volume for the test ordered.

4. Proper storage and transport — maintaining the sample at the correct temperature and delivering it to the lab promptly.

5. Proper analysis — using calibrated, maintained equipment and correct reagents, following established protocols.

6. Proper interpretation — by qualified personnel, with appropriate review and quality control.

7. Proper reporting — accurate transcription of results into the laboratory information system, with appropriate flags for critical values.

8. Proper communication — timely communication of results to the treating physician, with specific protocols for critical values.

When any link in this chain breaks, the results may be inaccurate — potentially leading to misdiagnosis, delayed diagnosis, or unnecessary treatment.

When Lab Errors Constitute Malpractice

Lab errors constitute medical malpractice when:

- The laboratory failed to meet the standard of care in collecting, handling, analyzing, interpreting, or reporting the test. - The error caused harm — a false negative delayed diagnosis of a serious condition (cancer, infection), a false positive led to unnecessary procedures, or a transcription error led to inappropriate treatment. - The laboratory failed to communicate critical results to the treating physician in a timely manner. - The pathologist or cytotechnologist misinterpreted the specimen — missing cancer or other serious conditions. [Link to: /misdiagnosis/pathology-biopsy-errors] - The treating physician failed to act on abnormal results — not following up on abnormal lab values or not communicating results to the patient. [Link to: /delayed-diagnosis-lawyer/failure-to-follow-up]

To prove malpractice, expert testimony from a laboratory medicine specialist, pathologist, or treating physician is required to establish the standard of care and how it was breached.

Who Is Liable for Lab Errors?

Multiple parties may be liable for a lab error, depending on where the error occurred:

- The phlebotomist or nurse who collected the sample — if the error was in collection or labeling. - The laboratory technician who performed the analysis — if the error was in testing. - The pathologist or cytotechnologist who interpreted the specimen — if the error was in interpretation. - The laboratory director — who is responsible for the overall quality and accuracy of the laboratory. - The laboratory corporation — such as Quest Diagnostics, LabCorp, or a hospital-based lab — under respondeat superior (vicarious liability for employees) and direct corporate liability. - The treating physician — who ordered the test and is responsible for acting on the results. If the physician failed to follow up on abnormal results or failed to communicate them to the patient, the physician may be liable. - The hospital or clinic — if the lab is part of a hospital or clinic system.

An experienced attorney will investigate the chain of custody and identify all potentially liable parties. [Link to: /hospital-negligence/credentialing-negligence]

Consequences of Lab Errors

The consequences of a lab error depend on the type of error and the condition involved:

• Delayed cancer diagnosis: A false negative biopsy or Pap smear can delay cancer diagnosis — allowing the cancer to progress to a more advanced stage with worse prognosis. [Link to: /medical-malpractice/cancer-misdiagnosis] [Link to: /misdiagnosis/pap-smear]
• Unnecessary cancer treatment: A false positive can lead to unnecessary biopsies, surgeries, chemotherapy, or radiation — with significant physical and emotional harm.
• Delayed infection diagnosis: A false negative culture can delay treatment of serious infections — potentially leading to sepsis or death. [Link to: /medical-malpractice/failure-to-diagnose-infection]
• Inappropriate medication: Incorrect lab results (e.g., false high potassium) can lead to inappropriate medication adjustments — potentially causing harm.
• Unnecessary procedures: A false positive can lead to unnecessary procedures (biopsies, cardiac catheterizations, surgeries) — with associated risks and complications.
• Psychological harm: The anxiety and emotional distress of a false positive diagnosis — or the realization that a diagnosis was delayed — can cause significant psychological harm.
• Financial harm: Additional medical expenses, lost wages from unnecessary treatment or delayed recovery, and the cost of corrective treatment.

Proving Causation in Lab Error Cases

Proving that a lab error caused the patient's harm requires establishing:

1. The standard of care was breached: Expert testimony that the laboratory failed to meet the standard of care in collecting, handling, analyzing, interpreting, or reporting the test.

2. The error caused the harm: Expert testimony linking the lab error to the patient's injury — a false negative delayed diagnosis, a false positive led to unnecessary treatment, or a transcription error led to inappropriate care.

3. Earlier accurate diagnosis would have prevented the harm: Expert testimony that if the lab error had not occurred, the diagnosis would have been made earlier, treatment would have been different, and the harm would not have occurred or would have been less severe.

4. Damages: Documentation of the additional medical expenses, lost wages, pain and suffering, and other harm caused by the error.

The defense may argue that the error did not cause the harm (the condition would have progressed regardless), that the treating physician should have recognized the error, or that the patient contributed to the harm. Expert testimony is required to counter these arguments. [Link to: /misdiagnosis/differential-diagnosis]

New York Statute of Limitations

Under CPLR § 214-a, the statute of limitations is 2.5 years from the date of the lab error. The continuous treatment doctrine may extend the deadline if you continued receiving treatment from the same provider for the same condition. Lavern's Law provides a discovery rule for cancer misdiagnosis cases — 2.5 years from discovery, with a 7-year outer limit. [Link to: /misdiagnosis/laverns-law] [Link to: /surgical-errors/statute-of-limitations]

Frequently Asked Questions

The value of a medical malpractice case in New York depends on several factors, including the severity of the injury, the strength of liability evidence, and the economic and non-economic damages involved. New York is one of the few states with no caps on medical malpractice damages, meaning there is no artificial limit on what you can recover. Below are typical settlement ranges based on injury severity.