Throughout the past several decades, the USA has placed increasing focus on the elimination of health disparities [1]. Attempts to establish whether progress is being made on this front have commonly included the examination of selected health metrics, but less commonly assess progress by examining several metrics simultaneously. One particular area of concern is disparities among different racial and ethnic groups. We thus chose this area for analysis and examined racial disparities for 17 health status indicators (HSIs) for the non-Hispanic White and non-Hispanic Black populations in Chicago and the USA in 1990 and 2010. Fourteen of these measured mortality, one measured birth outcomes (other than infant mortality), and two measured infectious diseases.
For the USA, we found that the racial disparity (measured by the percentage difference) narrowed significantly for 8 of the 17 HSIs over the 20-year period, while 1 other indicator improved but not significantly. Thus, slightly more than half of the health status indicators moved toward equality over the interval. At the same time, the disparities in eight indicators widened and six significantly so.
The situation in Chicago was far worse than for the USA. Of the 17 health status indicators examined, 8 narrowed, but only 3 significantly so. Conversely, nine indicators widened and four significantly so. What this looks like for individual HSIs is sobering. In 1990, the Black all-cause mortality rate was 35.6 % higher than the White rate. Twenty years later, the disparity had not decreased at all and was 37.7 %. Equally alarming is the fact that some of these disparities actually appear to have grown between 2005 and 2010. For instance, as reported by Orsi et al., the percentage difference in Black:White heart disease mortality in 2005 was 24.3; this increased to 27.5 by 2010 [9]. The same widening is observed for diabetes mortality, where the percentage difference grew from 67.0 in 2005 to 69.9 in 2010. A similar pattern is observed for motor vehicle crash and homicide mortality. Thus, not only have we observed a widening of disparities between 1990 and 2010, we also see that even in the very recent past (2005 to 2010), disparities have been continuing to widen for several health status indicators.
One mortality measure of note is the infant mortality rate (IMR). In the USA, the disparity was 135 % in 2010, precisely the same that it was 20 years earlier. In 2010, the Black IMR was 12.0 (infant deaths per 1,000 live births). In Chicago, the disparity shrank from 208 % in 1990 to 151 % in 2010. Despite this improvement, the Black IMR in Chicago was 11.3 in 2010. This rate is higher than the overall rate for 56 countries in the world, including for example Cuba, Slovenia, and Bulgaria [19].
The other birth outcome measure included here, the percentage of low birthweight babies, decreased significantly in both Chicago and the USA, but the disparity was still close to 100 % in 2010. The decreasing disparity for low birthweight was particularly interesting. In the USA, the rates for both Blacks and Whites grew worse over the 20-year interval; however, since the White rate worsened more than the Black rate, the disparity actually declined. In Chicago, the Black rate improved slightly over the period, while the White rate worsened slightly, thus leading to a decline in the disparity.
We also analyzed two measures of infectious diseases, tuberculosis, and syphilis. In both the US and Chicago, the disparity for tuberculosis decreased a small but significant amount while the disparity for syphilis decreased a great deal but was still close to 700 % in the US in 2010.
We also calculated the number of excess Black deaths attributable to the Black:White mortality disparity. Though not commonly reported, this metric provides a simple and easy-to-understand number which quantifies the effect of the mortality gap. According to an article by Satcher and his colleagues, in 2002, there were 83,570 excess African American deaths in the USA [20]. The present analysis estimates that the number of excess Black deaths in the USA in 2010 was 60,923. While this is a substantial improvement, this is still 21 % of all Black deaths. In Chicago in 2010, there were 2,454 excess Black deaths, accounting for 28 % of the total. This means that on an average day in Chicago in 2010, almost seven Black people died because the Black death rate was so much higher than the White rate. Thus, despite the national focus on mitigating disparities in health, this analysis shows that there has been no progress for the country as a whole and that Chicago is regressing.
Link and Phelan have clearly shown how it is possible (even inevitable) that general health could improve while disparities could worsen [21]. Indeed, in order to fight against such disparities, we will have to fight against both the fundamental causes like racism and poverty [21–23] as well as the derivative (or proximal or downstream) issues like segregation [24–27], inadequate housing [28], inadequate health care [29, 30], etc.
If racial disparities in health are to be eliminated, the fundamental causes must be addressed. While this process will no doubt take time, there are several steps that can be taken more immediately to work toward health equity. Examples of things that can be done before we are able to eliminate racism and poverty include determining where problem areas are and then developing and implementing appropriate health interventions in those areas [31, 32].
One way in which we can gain a better understanding of where our problem areas are is by performing analyses for geographic units below the national level (like the one presented in this paper). An examination of data below the national level can reveal which health conditions need to be addressed for specific localities since national averages mask local variation. This is clearly demonstrated in the present analysis where large differences are observed between the rates and disparities at the national level and those in Chicago. Similarly, we have performed analyses of diabetes and breast cancer mortality for the 50 largest US cities and found that mortality rates and disparities therein vary greatly across the USA [33, 34]. It is even possible (and encouraged) to take these analyses further and examine data for neighborhoods/communities within cities. We have performed such analyses for Chicago for diabetes [35, 36] and stroke [37] mortality, as well as maternal smoking [38] and have found that rates vary tremendously across community areas within Chicago.
This type of data has allowed us to develop more targeted responses, focusing on areas we have determined to have higher rates of mortality. For example, as a result of these types of analyses, we have implemented Community Health Worker-based health interventions for diabetes, breast cancer, and pediatric asthma, targeting those Chicago communities which have been found to bear a disproportionate burden of these conditions. Additionally, data like these are key to catalyzing action. For example, in response to these data, the Metropolitan Breast Cancer Task Force was formed to eliminate disparities in breast health in Chicago [39, 40] and a community-based organization was developed to address the high rates of diabetes mortality in one Chicago community [41].
Methodological Considerations
Throughout this report, we have emphasized health disparities between Blacks and Whites and shown that these disparities are a major challenge facing the USA. However, we recognize that disparities likely exist among several other racial and ethnic groups, as well as between persons of differing SES, physical and mental abilities, sex, gender, etc. We consider this an important direction for future research.
It is also essential to point out that Black:White disparities can form and even increase while both rates improve, worsen, or move in opposite directions. Thus, for example, the Chicago disparity in heart disease mortality widened significantly over the 20 years despite the fact that both the Black and White rates improved substantially over the interval. The breast cancer mortality rate also widened (p = 0.10) and this occurred while the Black rate declined a little but the White rate declined dramatically. Most of the HSIs improved but this did not generally narrow disparities.
There are several ways to measure disparities [16, 42–45]. We have chosen to use the method of relative differences since it is consistent with our more recent previous report on this topic [9] which in turn was generated to be consistent with the paper generally regarded as the gold standard in this field [46].