This paper reports the results of an experimental study to evaluate the effectiveness of three qualified health claim schemes for conveying information to consumers about emerging scientific evidence about certain diet-disease relationships. The three schemes include: (1) the current word-only scheme employed by FDA in which claims that meet the standard of significant scientific agreement (SSA claims) contain no language referring to the level of scientific evidence, and other claims are qualified by a disclaimer; (2) a word-only scheme in which SSA claims contain language referring to the level of scientific evidence, and other claims contain disclaimers referring to the levels of scientific evidence; and (3) a report card scheme in which SSA claims receive a grade “A,” other claims receive grades “B,” “C,” or “D,” and all claims are prefaced with the phrase “FDA says that the science behind this claim is (grade).”
The study examines the schemes using four qualified health claims currently allowed under enforcement discretion and two SSA claims. Each of the schemes is evaluated against three performance standards: (1) the ability of disclaimers to mitigate erroneous respondent perceptions of the level of scientific evidence for a claim as compared to an unqualified claim; (2) the ability of disclaimers to convey distinct and successive levels of scientific evidence for health claims; and (3) the impact disclaimers have on other product perceptions, including health benefits, as compared to an unqualified health claim and a no-claim control.
Each of the schemes exhibits some level of success and some level of failure against the three standards. None of the schemes was entirely effective at conveying the intended levels of scientific evidence supporting health claims. Although the schemes show effectiveness at communicating levels of evidence for less supported (i.e., C and D-level) claims, none of the schemes is consistently capable of highlighting the distinction between SSA claims and claims with the next (lower) level of scientific evidence.