Historians' testimony on "common knowledge" of the risks of tobacco use: a review and analysis of experts testifying on behalf of cigarette manufacturers in civil litigation.

A qualitative analysis of the trial and deposition testimony of professional historians who have testified on behalf of the tobacco industry shows that defence historians present a view of past knowledge about tobacco in which the public was frequently warned that cigarettes were both deadly and addictive over the broad historical period. While defence historians testify to conducting significant levels of independent research, they also draw upon a common body of research conducted by industry counsel to support its litigation efforts. Defence historians unduly limit their research materials, ignoring industry records and, therefore, critically undermine their ability to evaluate industry activity in the smoking and health controversy as it unfolded in historical time. A consequence is that defence historians present a skewed history of the cigarette in which the tobacco industry all but ceases to exist.