Figure 1. Diabetes trends across income levels as related to race.

A Cochran-Armitage trend test revealed a statistically significant trend in the prevalence of diabetes related to income level, with the highest income quartile having the lowest prevalence of diabetes (P<.001) among White patients. This difference is not seen among Black patients (P=.214). A chi-square test showed that Black patients have a statistically significant higher overall prevalence of diabetes than White patients in all income quartiles (P<.001). Median household income quartiles, from first to fourth, were <$35,229, $35,230-$49,518, $49,519-$67,777, and >$67,778. IQ, interquartile.