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

It Is Not Just the Southeast-Geographically Pervasive Racial Disparities in Neisseria gonorrhoeae Between Non-Hispanic Black and White US Women

Background:

Spatial analyses of gonorrhea morbidity among females often highlight the southeastern US but may not provide information on geographic variation in the magnitude of racial disparities; such maps also focus on geographic space, obscuring underlying population characteristics. We created a series of visualizations depicting both county-level racial disparities in female gonorrhea diagnoses and variations in population size.

Methods:

We calculated county- and region-level race-specific relative rates (RelR) and between-race rate differences (RD) and rate ratios (RR) comparing gonorrhea case rates in non-Hispanic Black (NHB) vs non-Hispanic White (NHW) females. We then created proportional symbol maps with color representing counties’ RelR/RD/RR category and symbol size representing counties’ female population.

Results:

Gonorrhea rates among NHB females were highest in the Midwest (718.7/100,000) and West (504.8), rates among NHW females were highest in the West (74.1) and Southeast (72.1). RDs were highest in the Midwest (654.6 excess cases/100,000) and West (430.7), while RRs were highest in the Northeast (12.4) and Midwest (11.2). Nearly all US counties had NHB female rates ≥3x those in NHW females, with NHB females in most highly populated counties experiencing ≥9-fold difference in gonorrhea rates.

Conclusions:

Racial disparities in gonorrhea were not confined to the Southeast; both relative and absolute disparities were equivalent or larger in magnitude in areas of the Northeast, Midwest, and West. Our findings help counter damaging regional stereotypes, provide evidence to refocus prevention efforts to areas of highest disparities, and suggest a useful template for monitoring racial disparities as an actionable public health metric.

Racial disparities in female gonorrhea rates are not confined to the Southeast; both relative and absolute disparities are equivalent or larger in areas of the Northeast, Midwest, and West.

Investigating the Impact of Using an Alternate Classification Method for Race and Hispanic Ethnicity on Rates of Reported Gonorrhea

BACKGROUND

We aimed to examine how the classification of gonorrhea cases by race and Hispanic ethnicity (HE) affects the measurement of racial/HE disparities in the rates of reported gonorrhea.

METHODS

We examined gonorrhea cases reported through the National Notifiable Diseases Surveillance System from January 1, 2010, to December 31, 2017, and assigned race and HE using (1) "current classification," where cases with HE are classified as Hispanic regardless of race (e.g., Hispanic, non-Hispanic White, and non-Hispanic Black), and 2) "alternate classification," which separates each race category by HE (e.g., Hispanic White and non-Hispanic White). We estimated annual gonorrhea rates during 2010 to 2017 by race/HE category and calculated disparity measures (index of disparity, population-attributable proportion, and Gini coefficient) for gonorrhea rates under each classification strategy.

RESULTS

All disparity measures revealed decreases in racial/HE disparities in the rates of reported gonorrhea during 2010 to 2017, regardless of classification strategy; however, the magnitude of the disparity and the percent change in the disparity over time varied across disparity measures.

CONCLUSIONS

Understanding how classification of race/HE affects observed disparities is critical when monitoring interventions to reduce disparities and improve health equity.

Patterns of Racial/Ethnic Disparities and Prevalence in HIV and Syphilis Diagnoses Among Men Who Have Sex With Men, 2016: A Novel Data Visualization

OBJECTIVES

To describe disparities in HIV infection and syphilis among gay, bisexual, and other men who have sex with men (MSM) in US states through ratio-based measures and graphical depictions of disparities.

METHODS

We used state-level surveillance data of reported HIV and syphilis cases in 2015 and 2016, and estimates of MSM population sizes to estimate HIV and syphilis prevalence by race/ethnicity and rate ratios (RRs) and to visually display patterns of disparity and prevalence among US states.

RESULTS

State-specific rates of new HIV diagnoses were higher for Black than for White MSM (RR range = 2.35 [Rhode Island] to 10.12 [Wisconsin]) and for Hispanic than for White MSM (RR range = 1.50 [Tennessee] to 5.78 [Pennsylvania]). Rates of syphilis diagnoses were higher for Black than for White MSM in 42 of 44 states (state RR range = 0.89 [Hawaii] to 17.11 [Alaska]). Scatterplots of HIV diagnosis rates by race showed heterogeneity in epidemic scenarios, even in states with similar ratio-based disparity measures.

CONCLUSIONS

There is a widely disparate impact of HIV and syphilis among Black and Hispanic MSM compared with White MSM. Between-state variation suggests that states should tailor and focus their prevention responses to best address state data.