Epidemiology and the law: courts and confidence intervals

Our plain-English summary of Epidemiology and the law: courts and confidence intervals, by T. Christoffel, S.P. Teret (American Journal of Public Health, 1991).

The study

• Authors: T. Christoffel, S.P. Teret
• Journal: American Journal of Public Health
• Published: 1991;81(12):1661-6
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Beginning with the swine flu litigation of the early 1980s, epidemiological evidence has played an increasingly prominent role in helping the nation's courts deal with alleged causal connections between plaintiffs' diseases or other harm and exposure to specific noxious agents (such as asbestos, toxic waste, radiation, and pharmaceuticals). Judicial reliance on epidemiology has high-lighted the contrast between the nature of scientific proof and of legal proof. Epidemiologists need to recognize and understand the growing involvement of their profession in complex tort litigation.

In plain English

This article is a commentary by two lawyers, not an original study of asbestos or any disease. It discussed how US courts have used epidemiological evidence in 'toxic tort' lawsuits, where plaintiffs claim harm from exposures such as asbestos, toxic waste, radiation and pharmaceuticals. Asbestos appeared only as one example. The authors reported that a computerized search of reported federal and state court opinions found words beginning with 'epidemiol' in three or fewer cases in each year from 1970 to 1973, and in 86 cases in 1990. They described several cases. In two 1982 swine flu vaccine cases, Sulesky and Cook, judges reached opposite conclusions on comparable evidence. In a nuclear fallout case, Allen v United States, the judge's decision was later reversed on other grounds. In Brock, a case over the drug Bendectin, an appeals court reversed a jury award. That court noted that the plaintiffs' analysis had a confidence interval of 0.17 to 3, which it called statistically insignificant. The authors concluded that scientific and legal proof differ, and that epidemiologists need to recognize their profession's growing role in tort litigation.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Commentary and legal analysis of court decisions (not an original epidemiological study)
• Who was studied: Reported US federal and state court opinions, plus selected cases: swine flu vaccine cases (Sulesky v United States, Cook v United States), Allen v United States (Nevada nuclear test fallout), and Bendectin cases (Brock and DeLuca v Merrell Dow)
• Exposure: No exposure was studied directly. Asbestos was mentioned only as one of many agents involved in toxic tort lawsuits, alongside dioxin, Agent Orange, radiation, lead paint, DES, vaccines and Bendectin.
• Main results:
  • In the authors' search of reported court opinions, words beginning with 'epidemiol' appeared in three or fewer cases per year from 1970 to 1973, and in 86 cases in 1990.
  • In two 1982 swine flu vaccine cases with comparable evidence, Sulesky and Cook, the courts reached opposite conclusions on causation.
  • Of more than 4000 swine flu claims against the US government, 2813 were denied and 1604 led to lawsuits; nearly two thirds of those lawsuits ended favorably to the government.
  • In Allen v United States, the trial judge used a 'reasonably exclusive factual connection test'. The decision was reversed on other grounds.
  • In Brock v Merrell Dow, the Fifth Circuit appeals court reversed a jury award. It noted that the plaintiffs' analysis found a relative risk of 1.49 with a confidence interval of 0.17 to 3, which the court called statistically insignificant.
• The authors' conclusion: The authors concluded that epidemiologists need to recognize their profession's growing involvement in complex tort litigation, and that scientific proof and legal proof differ in nature.

Topics

Medical terms in this study, explained in our Lexicon: Epidemiology, confidence interval, Plaintiff, Tort.

Related studies

• Toxicology and epidemiology: improving the science with a framework for combining toxicological and epidemiological evidence to establish causal inference — H.O. Adami, S.C. Berry, et al. (2011)
• Confidence interval function analysis to evaluate the risk of mesothelioma among an expanded international cohort of cosmetic talc miners and millers — G.M. Marsh, A.M. Ierardi (2020)
• Confidence Intervals for Asbestos Fiber Counts: Approximate Negative Binomial Distribution — D. Bartley, J. Slaven, et al. (2017)
• Forensic Epidemiology in Italy: principles and practice — V. Chiesa, A. Odone, et al. (2017)
• Corporate corruption of medical literature: asbestos studies concealed by W.R. Grace & Co — D. Egilman, W. Wallace, et al. (1998)
• Epidemiology: a foundation of environmental decision making — K.C.K. Deener, J.D. Sacks, et al. (2018)

Browse more research in American Journal of Public Health, or return to medical research.