Trends in Selected Measures of Racial and Ethnic Disparities in Gonorrhea and Syphilis in the United States, 1981–2013

Abstract

Background The purpose of this study was to examine selected measures of racial and ethnic disparities in the reported incidence of syphilis and gonorrhea from 1981 to 2013 in the United States. Methods For each year from 1981 to 2013, we calculated values for five disparity measures (Gini coefficient, two versions of the index of disparity, population attributable proportion, and the black-to-white rate ratio) for five racial/ethnic categories (Non-Hispanic White, Non-Hispanic Black, Hispanic, American Indian/Alaska Native, and Asian/Pacific Islander). We also examined annual and 5-year changes to see if the disparity measures agreed on the direction of change in disparity. Results With a few exceptions, the disparity measures increased from 1981 to 1993 and decreased from 1993 to 2013, whereas syphilis and gonorrhea rates decreased for most groups from 1981 to 1993 and increased from 1993 to 2013. Overall, the disparity measures we examined were highly correlated with one another, particularly when examining 5-year changes rather than annual changes in disparity. For example, all five measures agreed on the direction of change in the disparity of syphilis in 56% of the annual comparisons and in 82% of the 5-year comparisons. Conclusions Although the disparity measures we examined were generally consistent with one another, these measures can sometimes yield divergent assessments of whether racial/ethnic disparities are increasing or decreasing for a given STD from one point in time to another, as well as divergent assessments of the relative magnitude of the change.

Disparities in Incidence of Human Immunodeficiency Virus Infection Among Black and White Women — United States, 2010–2016

“…However, in 2016, although black women accounted for 13% of the U.S. female population, 60% of new HIV infections among women were in black women, indicating persisting disparities ( 1 ). CDC used the population attributable proportion (PAP) disparity measure to describe the proportional decrease in HIV infection among black and white women combined that would be realized if the group with the higher rate (blacks) had the same rate as did the group with the lower rate (whites) ( 2 ). Analyses indicated that an estimated 3,900 of 4,200 (93%) incident HIV infections among black women in 2016 would not have occurred if rates were the same for black and white women.…”

Using Reported Rates of Sexually Transmitted Diseases to Illustrate Potential Methodological Issues in the Measurement of Racial and Ethnic Disparities

“…To our knowledge, only 1 study has used multiple disparity measures to assess trends in racial/ethnic disparities in STDs over time. 15 This study reported that although measures of racial/ethnic disparities in STDs are often consistent with one another, these measures from 1 point in time to another can be increasing according to 1 measure and decreasing according to another. 15 The potential for inconsistencies between disparity measures in assessing changes in disparities over time is one of the well-known methodological issue associated with disparity measures.…”

“…A key theme across all 4 of our examples is that different disparity measures can provide divergent assessments of trends in disparities in STDs from one point in time to another, consistent with previous research. Chesson and colleagues 15 used 5 disparity measures to examine trends in racial/ethnic disparities in gonorrhea and syphilis. Although the 5 measures were generally consistent with one another, these measures sometimes provided different assessments of changes in disparities in STDs.…”

“…In an analysis of trends in racial/ethnic disparities in STDs, the Gini coefficient was more highly correlated with the Weighted Index of Disparity than with the Index of Disparity, in part because the Gini coefficient and the Weighted Index of Disparity both account for the population size of the racial/ethnic groups, whereas the Index of Disparity does not. 15 The methods we used to calculate these measures are described briefly here, and discussed in more detail elsewhere. 9–15,17–21…”

“…15 The methods we used to calculate these measures are described briefly here, and discussed in more detail elsewhere. 9–15,17–21…”