Chemical Safety Studies: Conrad and Becker Respond

Influence of design charac­ teris tics on the outcome of retrospective cohort studies. Br J Ind Med 45:624–629. vom Saal FS, Hughes C. 2005. An extensive new literature concerning low­dose effects of bisphenol A shows the need for a new risk assessment. Environ Health Perspect 113:926–933. Sutton et al. and Tweedale both criticize our review (Conrad and Becker 2011) because we did not include industry funding of a study in our proposed set of criteria. Fundamentally, we rejected " industry funding " as a credibility criterion " because questions can also arise about the credibility of research by scientists funded by government agencies or nonprofit organizations " (Conrad and Becker 2011). We accept as a given that someone has always paid for scientific work and that funding has inherent potential to influence results, whether it comes from industry, environmental groups, or government. It appears that at least one member of Sutton et al. agrees with us to some degree on this point, because they repeatedly cite Bero (1999), who endorsed " establishing restrictions on sponsorship, regardless of its source. " We agree that funding bias has been docu mented, at least in clinical trials for pharmaceuticals and medical procedures, although as Sutton et al. note, the published literature does not yet appear to have systematically studied the issue in the field of toxicology or epidemiology across a broad spectrum of substances. (Tobacco is a unique and extreme case and should be recognized as such, not cited tendentiously as indicative of all industry support of research.) The guidelines for routine toxicity studies are publically available and incorporate end points reflecting both input from a broad spectrum of experts and approval by government regulatory authorities [U.S. Environmental Protection Agency (EPA) 2011], and all such studies employ an entirely independent quality assurance program documenting that facilities, equipment, personnel, methods, practices, records, and controls are in conformance with Good Laboratory Practice (GLP) requirements. The extent to which these features govern the design and conduct of toxicity studies mitigates funding bias to a large degree. In our review (Conrad and Becker 2011), we also noted that source of funding is often considered a " less significant " cause of publication bias than other causes [e.g., career advancement (publish or perish), personal advancement, status in one's professional field, interest in obtaining positive results]. Sutton et al. attempt to show that the documents from ostensibly non industry-funded …