FDA Regulatory & Statistics Expert Witness
When a dispute turns on how the FDA evaluates statistical evidence, it helps to have an expert who has done that work from the inside. Lei Li, Ph.D., is a former FDA/CDRH primary statistical reviewer who can speak directly to the statistical standards the agency applies to device submissions — and translate them for judges and juries.
- Former FDA / CDRH Statistical Reviewer
- Ph.D. Statistics, George Mason University
- PMA · De Novo · 510(k) · IDE · RWE
- Plaintiff & Defense
When a case turns on FDA statistics
Many medical-device and regulatory disputes hinge on whether the statistical evidence behind an FDA submission was adequate, correctly analyzed, and fairly characterized. Dr. Li provides independent opinions in matters such as:
- Statistical adequacy of data supporting 510(k), PMA, De Novo, and IDE submissions.
- Clearance- and approval-probability questions, including how a submission's statistical evidence bears on the likelihood of FDA action.
- Real-world-evidence (RWE) studies and the use of propensity-score methodology to construct comparable groups.
- Disagreements over statistical methodology — analysis populations, endpoints, missing-data handling, and the interpretation of submitted results.
- Whether the design and analysis of a study matched what the regulatory pathway and the data could support.
How Dr. Li helps
Engagements are scoped to the questions in the case. Common roles include the following.
Methodology review
Independent assessment of the statistical methods used in a submission or study — design, endpoints, analysis populations, and the soundness of the conclusions drawn from the data.
Clearance-probability assessment
Evaluation of FDA clearance- or approval-probability calculations and the statistical reasoning that underlies them, including the assumptions on which such estimates rely.
Rebuttal of opposing experts
Critical analysis of opposing regulatory and statistical experts — identifying methodological errors, unsupported assumptions, and overstated conclusions.
Expert reports & declarations
Written expert reports and declarations that explain complex regulatory-statistical issues clearly and defensibly for the court.
Daubert support
Support on the reliability of statistical methods and the application of recognized standards, helping counsel address admissibility questions.
Counsel consultation
Behind-the-scenes consulting support to help counsel frame the statistical and regulatory issues, prepare cross-examination, and test the strength of each side's evidence.
Why a former FDA reviewer
From September 2020 to April 2022, Dr. Li served as a Mathematical Statistician and Primary Statistical Reviewer at the FDA's Center for Devices and Radiological Health (CDRH).
- An inside view of how FDA statistical review actually works — what reviewers look for and how statistical evidence is weighed within a submission.
- Hands-on review of PMA, De Novo, 510(k), IDE, pre-submission, and real-world-evidence submissions across therapeutic and diagnostic device types.
- Authored statistical memoranda for general surgical, orthopedic, and in vivo and in vitro diagnostic devices, and applied propensity-score methodology in RWE matters.
Non-affiliation notice. Dr. Li is a former FDA/CDRH statistical reviewer and is no longer affiliated with the FDA. This site is not affiliated with, endorsed by, or sponsored by the FDA or any government agency, and Dr. Li does not claim any special access to, contacts within, or influence over the agency. His value is technical and methodological: experience with how statistical evidence is evaluated, not any current relationship with the FDA.
FDA regulatory matters — FAQ
Can you opine on whether a device would have been cleared or approved?
Dr. Li can assess the statistical evidence behind a submission and the methodology used in any clearance- or approval-probability analysis, and explain what that evidence does and does not support. He does not guarantee outcomes or predict how a regulatory decision would have come out; opinions are framed around statistical adequacy and recognized methods.
Do you represent plaintiffs or defendants?
Both. Dr. Li accepts engagements from plaintiff and defense counsel. Every engagement is subject to a conflicts-of-interest check before work begins.
Does your former FDA role give you special access at the agency?
No. Dr. Li is a former CDRH statistical reviewer with no current FDA affiliation and no special access, contacts, or influence. The relevant value is his direct experience with how the agency evaluates statistical evidence in device submissions.
Are you available to write reports and testify?
Yes. Dr. Li welcomes testifying engagements, including expert reports, declarations, deposition, and trial, in addition to behind-the-scenes consulting support. Availability is confirmed after a conflicts check and a signed engagement agreement.
Discuss an FDA regulatory-statistics matter
If your case involves an FDA device submission, clearance probability, or a dispute over statistical methodology, request a confidential consultation to discuss scope, timing, and conflicts.