New and improved: the role of text augmentation and the application of response interpretation standards (coding schemes) in a final iteration of birth defects warnings development.

BACKGROUND Several birth defects warning symbols identified as most successful in an earlier study (Mayhorn and Goldsworthy, 2007) were further modified and then evaluated within a nationally distributed field trial (n = 2773). The purpose for the current research was to determine whether symbol warning components could be improved further, whether the addition of text enhanced comprehension uniformly across symbols, and whether results varied by the application of different interpretation standards (coding schemes). METHOD A total of 11 warning labels were examined: four new symbols plus the existing baseline symbol, each in versions with and without text, plus a text-only condition. Participant interpretation accuracy and preferences were assessed during face-to-face interview sessions. RESULTS For symbol-only conditions, several candidate symbols outperformed the existing symbol, one substantially so. The effect of adding text to symbols varied significantly by symbol. Symbol plus text and text-only conditions performed equivalently, generally exceeded symbol-only conditions, and often surpassed the American National Standards Institute benchmark of 85% accurate interpretation. CONCLUSIONS The research effort has identified a teratogen symbol and warning that outperforms the one currently in use. The effort has also identified important pragmatic and conceptual issues that should inform future work to improve medication labeling and other hazard communication.