Expert Witness Profiler

Tag: Public Health

  • Public Health Expert Was Allowed to Opine on the Quality of Care

    Public Health Expert Was Allowed to Opine on the Quality of Care

    This is a securities class action, led by Chicago Laborers’ Pension Fund and New York Hotel Trades Council & Hotel Association of New York City, Inc. Pension Fund (collectively, “Plaintiffs”).

    Plaintiffs alleged that Acadia Healthcare Company, Inc. (“Acadia”) and several of its current and former executives, including David M. Duckworth, Brent Turner, and Joey A. Jacobs (collectively, “Defendants”) made false and misleading statements to investors regarding Acadia’s business.

    Defendants filed a motion to exclude the testimony and opinions of Plaintiff’s expert witness Dr. Ashish K. Jha.

    Public Health Expert Witness

    Ashish Kumar Jha is an American general internist physician and academic who served as the White House COVID-19 response coordinator from 2022–2023. He has been Dean of the Brown University School of Public Health since 2020.

    Prior to Brown, he was the K.T. Li Professor of Global Health at Harvard T.H. Chan School of Public Health, faculty director of the Harvard Global Health Institute, and a Senior Advisor at Albright Stonebridge Group.

    Get the full story on challenges to Ashish Jha’s expert opinions and testimony with an in-depth Challenge Study.

    Discussion by the Court

    Defendants did not dispute that Jha is qualified as an expert to opine on the quality of care offered at Acadia’s mental healthcare facilities during the Class Period. Instead, they contended that his opinions on that issue should be excluded as irrelevant because he did not opine about the quality of care offered at Acadia’s facilities “on the whole,” and that his opinions about assessing the quality of care offered at Acadia’s mental health facilities should be excluded as unreliable for failing to provide factual context that Defendants think is important.

    Plaintiffs responded by first noting that Jha’s overarching opinions concerned the quality of care offered in all of Acadia’s facilities and that such evidence is highly probative of falsity as to the challenged quality care misstatements. Next, Plaintiffs argued that Jha’s opinions are reliable. Plaintiffs submitted that Defendants’ motion ignored Jha’s detailed explanation, supported by considerable scholarship, of why it was appropriate to compare Acadia’s standalone, for-profit inpatient facilities to other standalone, for-profit inpatient facilities to prevent confounding variables from prejudicing the analysis.

    The Court found that Plaintiffs have shown by a preponderance of the evidence that Jha is qualified, his opinions have a reliable basis in the knowledge and experience of his discipline, and that he will testify to knowledge that will assist the trier of fact in understanding the evidence about the quality of care offered at Acadia’s mental healthcare facilities during the Class Period and deciding whether Defendants’ challenged statements regarding the same were knowingly false when made.

    Held

    The Court denied the Defendants’ motion to exclude the testimony and opinions of Plaintiff’s expert witness Dr. Ashish K. Jha.

    Key Takeaway:

    Although the Defendants also attacked Jha’s methodology, those arguments did not show that Jha’s opinions are “so fundamentally unsupported that it can offer no assistance to the [trier of fact]” under the facts of this case.

    Please refer to the blog previously published about this case:

    Economics Expert Allowed to Opine on Stock Inflation

    Case Details:

    Case Caption: St. Clair County Employees’ Retirement System V. Acadia Healthcare Company, Inc. Et Al
    Docket Number: 3:18cv988
    Court Name: United States District Court for the Middle District of Tennessee, Nashville Division
    Order Date: November 07, 2025
  • Preventive Medicine Expert Was Allowed to Opine on the Clinical and Operational Duties

    Preventive Medicine Expert Was Allowed to Opine on the Clinical and Operational Duties

    On January 28, 2021, Demetrius Nichols died while incarcerated at Menard Correctional Center. Plaintiff Diane Jones, Administrator of the Estate of Demetrius Nichols, filed this action against Wexford Health Sources, Inc., Dr. Mohammed Siddique, Ali Dearmond, NP, and Dr. Stephen Ritz, asserting wrongful death.

    Plaintiff retained Ryan D. Herrington, M.D., MPH to support her claims. Defendants filed a motion to exclude the testimony of Herrington.

    Preventive Medicine Expert Witness

    Ryan Douglass Herrington, M.D., MPH received his medical degree from the University of Virginia and a master’s degree in public health from the Ohio State University. He is licensed to practice medicine and is dual board certified by the American Board of Preventive Medicine in both public health/preventive medicine and addiction medicine.

    Get the full story on challenges to Ryan Herrington’s expert opinions and testimony with an in-depth Challenge Study.

    Discussion by the Court

    Herrington opined to a reasonable degree of medical certainty that: (1) from an asthma perspective, Nichols would have benefitted from earlier referral to otolaryngology; (2) Wexford practitioners’ repeated use of steroids for Nichols amounted to customary maintenance treatment for his nasal polyps; (3) Wexford’s custom of using steroids for nasal polyps was harmful for Nichols; (4) Wexford’s custom of using steroids for Nichols made it increasingly likely that he would suffer an asthma exacerbation; and (5) Wexford’s failure to provide Nichols a higher level of care on January 25, 2021 and on January 26, 2021 was a breach of the standard of care.

    Qualification

    Defendants argued that Herrington’s opinions should be excluded because he sought to opine on matters outside of his area of expertise and failed to review sufficient facts and data to form reliable opinions. Defendants further contended that his opinions are not grounded in reliable methodology. The Court disagreed.

    Herrington had the requisite background and experience to render opinions regarding the medical care Nichols received while incarcerated. He has over a decade of experience in correctional medicine, including as a former medical director of a state prison. Herrington testified that he was either directly or indirectly involved with every patient at those correctional facilities. His experience renders him qualified to opine regarding the clinical and operational duties at issue in this case.

    Reliability

    Defendants also argued that Herrington’s opinions are unreliable. In reaching his opinions, Herrington reviewed relevant case materials, including medical records and deposition testimony. He applied his extensive experience to evaluate the facts of this case and reached his conclusions regarding the medical care provided to Nichols. Herrington’s report includes a detailed methodology section in which he outlines and explains how he grounded his analysis in the medical records and treatment chronology. Herrington referenced numerous sources he relied on in formulating his opinions.

    Defendants’ disagreements with Herrington’s ultimate conclusions are not a justifiable basis to exclude his opinions. Defendants may certainly attempt to discredit Herrington on cross-examination or in their own presentation of the evidence. But their arguments go to the weight to be given Herrington’s testimony, not to its admissibility.

    The Court held that his opinions are relevant and will assist the jury with its analysis of whether Defendants’ care fell below accepted practice and caused or contributed to Nichols’ death. 

    Held

    The Court denied the Defendants’ motion to exclude the testimony of Ryan Herrington.

    Key Takeaway

    In sum, the reliability of data and assumptions used in applying a methodology is tested by the adversarial process and determined by the jury; the court’s role is generally limited to assessing the reliability of the methodology — the framework — of the expert’s analysis.

    Defendants’ disagreements with Herrington’s ultimate conclusions are not a justifiable basis to exclude his opinions.

    Case Details:

    Case Caption: Nichols V. Wexford Health Sources, Inc
    Docket Number: 3:24cv796
    Court Name: United States District Court, Illinois Southern
    Order Date: December 03, 2025
  • Infectious Disease Expert’s Statements on Employer Liability Excluded

    Infectious Disease Expert’s Statements on Employer Liability Excluded

    Plaintiffs, former employees of a local government public health agency, each filed suit against Rock Island County Health Department (“RICHD”) and Rock Island County, Illinois (“the County”) alleging that their previous employer, RICHD, violated Title VII of the Civil Rights Act of 1964.

    The purported violations stem from their employer’s failure to accommodate their religious beliefs, first, when it denied their exemptions from a COVID-19 vaccination requirement, and later when Plaintiffs were terminated for failing to get vaccinated.

    RICHD disclosed an expert witness, Dr. F. Ramzi Asfour. Asfour was asked to “provide his opinion concerning the proper approach of a public health entity to evaluating requests from employees to be exempted from” vaccination requirements and to provide epidemiological evidence related to vaccine efficacy compared to other mitigation methods.

    Plaintiffs filed the instant motion to bar Asfour, arguing that his opinion violated the standards of Federal Rules of Evidence 702 and 704.

    Infectious Disease Expert Witness

    F. Ramzi Asfour, MD, is board certified in Infectious Diseases and Internal Medicine, having attended a fellowship specializing in infectious
    diseases and having worked for the World Health Organization.

    His experience practicing medicine in the area of infectious diseases spans seventeen years, with over 72,000 patient encounters. Moreover, he has recent experience in consulting hospitals and other healthcare facilities on “policies, procedures and protocols relating to COVID-19.”

    Get the full story on challenges to F. Ramzi Asfour’s expert opinions and testimony with an in-depth Challenge Study. 

    Discussion by the Court

    Whether the Statements Fall Outside of Asfour’s Expertise

    Plaintiffs state that Asfour is a medical doctor with an expertise in public health who “is not qualified to render opinions regarding religion or religious exemptions.”

    The Court held that Asfour did not purport to opine about the sincerity of anyone’s religious beliefs. Instead, he highlighted various reasons that it was important from a public health perspective that healthcare workers be vaccinated, and based on those factors, opined that healthcare entities should carefully scrutinize requests for religious exemptions from COVID-19 vaccination requirements. Further, he opined that the scrutiny should be accomplished by identifying whether there was a “clear and specific doctrinal basis for objecti[ng]” to getting the vaccine. This is not a religious opinion, so Plaintiffs’ argument that Asfour should be barred from testifying that “religious exemptions should generally be denied unless there is a clear and specific doctrinal basis for objection” on the basis that it is outside his expertise is denied.

    Whether the Opinion Contains Legal Conclusions

    Asfour opined on how “employer liability” is affected by a potential COVID-19-
    related illness or death. And, while Plaintiffs do not take issue with
    this part of the opinion, Asfour recounts, verbatim, the definition of religion under Title VII.

    While allowing Asfour to opine as to the definition of religion under Title VII and interpret an employer’s liability related to COVID-19 illness or death would run the risk of confusing a jury with multiple presentations of the law, the Court held that Asfour’s statements also offer his perspective on public health matters and provide background for RICHD to make its arguments related to whether granting religious exemptions constituted an undue burden.

    Therefore, the Court will limit Asfour’s opinion as to his statement on employer liability related to COVID-19 illness or death, and the definition of religion under Title VII. Those are matters designated for the Court to instruct on; all other statements do not constitute legal conclusions.

    Whether the Opinion Meets the Standards of Reliability

    From what the Court can decipher from Plaintiffs’ motion, they did not challenge that the underlying data or methodologies used to formulate Asfour’s opinion were unreliable; however, they seemingly did contend that his opinion cannot meet the requirements under Rule 702(d).

    Asfour began his expert report by outlining “[a] meta-analysis with seven studies with 21,618,297 COVID-19 patients,” and explained how “unvaccinated patients were 2.46 times more likely to die from COVID-19.”

    He analyzed the drop in the death rate after the introduction of the vaccine, specifying how the weekly deaths in Rock Island County decreased from five to one from late 2021 to early 2022.

    Asfour then discussed how religious groups generally did not object to vaccinations from a public health standpoint.

    The Court held that Asfour’s application of data to the facts at hand did not run afoul of what was required under Rule 702(d).

    Whether the Opinion is Relevant

    Plaintiffs argued that much of Asfour’s opinion consisted of mere “facts which appear solely intended to justify the vaccine mandate itself which is not the issue for this jury.”

    However, the Court held that Asfour’s opinion will aid the factfinder by providing a better understanding of how the rates of infection during the COVID-19 pandemic changed based on the availability and use of the vaccine, which connects to the analysis of whether RICHD faced an undue burden in granting exemption requests.

    Plaintiffs next argue that the opinion is too vague due to Asfour’s use of words like “most,” “many,” and “generally.”

    Since RICHD has met its burden in establishing how the expert opinion will aid the finder of fact, the Court held that Asfour’s opinion is not too vague to provide this background.

    Held

    The Court granted in part and denied in part the Plaintiffs’ motion to bar or exclude Defendant Rock Island County Health Department’s expert F. Ramzi Asfour.

    Key Takeaway:

    Asfour has over seventeen years of experience in treating infectious diseases and has recently shifted his career to consulting healthcare entities specifically on COVID-19 responses—expertise that he pulls from to formulate his opinion. Moreover, his expert opinion meets the relevant standards; he is qualified to opine on matters of public health, his methodology was reliable, and the testimony is relevant.

    However, Asfour cannot opine on the definition of religion under
    Title VII or employer liability related to COVID-19 illness or death.

    Case Details:

    Case Caption: Sanchez V. Rock Island County Health Department
    Docket Number: 4:23cv4007
    Court Name: United States District Court for the Central District of Illinois, Rock Island Division
    Order Date: May 12, 2025
  • Pediatrics Expert’s Opinion Regarding a Target 95% Vaccination Rate Met the Daubert Bar

    Pediatrics Expert’s Opinion Regarding a Target 95% Vaccination Rate Met the Daubert Bar

    On July 22, 2022, Dr. Gregory Fox, individually and as parent of C.F., and Rita Fox, individually and as parent of C.F. (jointly, the Plaintiffs), filed a lawsuit challenging the state of Maine’s public school vaccination requirements.

    Dr. Laura Blaisdell, a pediatrician with extensive qualifications in medicine and public health, was presented as an expert witness by Department of Education Commissioner Pender Makin. Fox’s challenge centered on Blaisdell’s opinion regarding a 95% vaccination rate target. He argued that her reliance on the R0 variable, which assumes a “totally susceptible” population, was unreliable and unsupported by scientific methodology when applied to the case’s specific facts. He claimed her assumption was erroneous because the population in question was only “partially susceptible”.

    Furthermore, Fox contested the scientific support for the 95% vaccination coverage goal, asserting that Blaisdell erred in inferring its necessity to protect susceptible individuals or halt disease transmission.

    Pediatrics Expert Witness

    Laura L. Blaisdell, MD, MPH, FAAP, CPE is a board-certified pediatrician, public health consultant, and researcher with expertise in vaccine hesitancy, infectious disease control, and camp medicine. She holds a Doctor of Medicine (MD) from the University of Minnesota Medical School and a Master of Public Health (MPH) from the University of Minnesota School of Public Health. She is also a Certified Physician Executive (CPE) and a Fellow of the American Academy of Pediatrics (FAAP).

    Blaisdell has served as an Attending Physician in the Department of Pediatrics at Maine Medical Center since 2008 and is an Assistant Professor at Tufts University School of Medicine. Her research and clinical work focus on vaccine decision-making, public health policy, and disease prevention in communal settings, particularly youth camps. She has been a key figure in vaccine advocacy and has contributed to legislative efforts to promote immunization policies.

    Want to know more about the challenges Laura Blaisdell has faced? Get the full details with our Challenge Study report. 

    Discussion by the Court

    Commissioner Makin countered that Fox conflated herd immunity threshold rates with public health vaccination targets for schools. They argued that Blaisdell’s use of R0 was a generally accepted practice for determining herd immunity thresholds.

    Regarding the 95% target, the Commissioner emphasized that it was a public health goal, not a herd immunity threshold, aligning with targets set by the United States Centers for Disease Control and Prevention (U.S. CDC) and the Maine Center for Disease Control and Prevention (Maine CDC). Blaisdell, in her deposition, clarified the distinction, stating that the 95% figure represents a public health recommendation for school vaccination levels.

    Analysis

    The Court acknowledged that Blaisdell’s use of R0 to calculate herd immunity thresholds was supported by scientific literature, including articles cited by both parties. While the use of this methodology in other scientific literature is not conclusive, it did demonstrate a measure of acceptance within the scientific community.

    The Court ruled that Fox’s challenge regarding the “partially susceptible” population goes to the weight and credibility of Blaisdell’s testimony, not its admissibility. The Court also recognized the distinction between herd immunity thresholds and public health vaccination goals.

    Blaisdell’s reliance on sources like the CDC and state health reports, as well as her clear explanation during deposition, provided sufficient support for the 95% target as a public health goal. Moreover, Blaisdell sufficiently distinguished herd immunity threshold calculations from the public health goal of 95% vaccination coverage. Therefore, challenges to the weight and credibility of the 95% goal did not prevent the testimony from being admissible.

    Held

    The Court dismissed without prejudice Gregory Fox’s motion to partially exclude the testimony of Dr. Laura Blaisdell.

    Key Takeaway:

    This case highlights the importance of distinguishing between different types of scientific targets, such as herd immunity thresholds and public health goals. It also demonstrates the Court’s role in evaluating the reliability and relevance of expert testimony under the Daubert standard. The Court’s decision emphasizes that challenges to the factual underpinnings of expert opinions primarily affect their weight and credibility, not necessarily their admissibility.

    Case Details:

    Case Caption: Fox Et Al V. Makin Et Al
    Docket Number: 2:22cv251
    Court: United States District Court, Maine
    Order Date: March 10, 2025