Hypotheses 1 and 2 state that the number of articles combining the topics of race, genetics, and health and the number of articles resembling the Backdoor Vignette increased significantly from 1985 to 2008. Figure 1 shows results pertaining to these hypotheses, as well as the total number of articles on race and genetics over this time period. Consistent with our hypotheses, a time-trend analysis, using General Estimating Equations to adjust for time-related correlated error, found that, despite clearly visible fluctuations over time, the number of articles increased significantly from 1985 through 2008 for each type of article (p < .001 for health-related articles and total articles about race and genetics; p < .01 for articles resembling the Backdoor Vignette).
