ABSTRACT
Despite the wide application of warnings in real-world situations, there has been surprisingly little field or populationbased research on effectiveness. Available field research has dealt mostly with public health warnings and can be organized into four areas: food products and dietary information and warnings; tobacco product warnings; alcoholic beverage warnings; and medication information and warnings. Research pertinent to each of these areas is reviewed in this chapter. On the basis of this review, several conclusions appear warranted. First, well-designed warnings do have the potential to reach targeted high-risk populations and can alter consumer choice behaviors. These impacts, however, are often modest and variable, and recipients may not always use the information as intended. Second, very few studies have involved actual health or injury outcomes. As in the general warnings literature, most studies
rely on surrogate measures and/or self-report data. This conclusion notwithstanding, there have been some innovative uses of time series designs and behavior-linked measures such as product sales. Third, available field studies show that it can be very difficult to segregate the effects attributable to the warning itself from other ongoing public health activities and secular trends. Fourth, care should be taken in extrapolating the results of these studies to other warning applications. Most of these warning applications do not involve hazard situations in which there is a high probability of immediate adverse consequences. A warning that provides a timely reminder about an immediate hazard is different from one intended to help individuals identify new hazards or modulate their long-term health risks. And fifth, there is a continuing need for studies that utilize control groups and/or randomized samples. Case-control and other epidemiological research designs may also prove useful for examining the contribution of warnings to health and injury outcomes.
