Unequal Declines in Absolute and Relative Disparities in HIV Diagnoses Among Black Women, United States, 2008 to 2016

Abstract

Objectives. To assess changes in disparities of HIV diagnosis rates among Black women aged 18 years or older living in the United States.

Methods. We calculated estimated annual percent changes (EAPCs) in annual diagnosis rates, rate differences (absolute disparity), and rate ratios (relative disparity) for groups (total, US-born, and non–US-born) of Black women (referent was all White women) with diagnosed HIV infection, using data reported to the National HIV Surveillance System.

Results. Of 39 333 Black women who received an HIV diagnosis during 2008 to 2016, 21.4% were non–US-born. HIV diagnosis rates declined among all Black women, with the smallest decline among non–US-born groups (EAPC = –3.1; P ≤ .001). Absolute disparities declined for both US-born and non–US-born Black women; however, the relative disparity declined for Black women overall and US-born Black women, whereas it increased for non–US-born (including Caribbean- and Africa-born) Black women.

Conclusions. Differences in disparities in HIV diagnoses exist between US-, and non–US-born (specifically Caribbean- and Africa-born) Black women. Accounting for the heterogeneity of the Black women’s population is crucial in measuring and monitoring progress toward eliminating health disparities among Black women.

In the United States, remarkable improvements have been made in diagnosing, treating, and preventing HIV infections. During 2003 to 2014, the number of HIV infection diagnoses declined 25% among the US population and 47% among the female US population.¹ The annual rate of HIV diagnosis among US Black females declined from 38.7 per 100 000 population in 2010 to 30.0 per 100 000 population in 2014.² Encouraging progress has also been made in reducing annual HIV diagnosis rates^1,3,4 and narrowing absolute and relative disparities in HIV diagnosis rates between Black women and women of other racial groups.^2,5

Progress among Black women has not been uniform across all groups of Black women, with HIV diagnosis rates continuing to be high among non–US-born Black women.⁴ Studies have consistently identified higher HIV diagnosis rates among non–US-born Blacks, especially Africa-born women.^4,6,7 Disparity is a difference in the health of a selected population linked with social, economic, or environmental disadvantages. Accounting for the heterogeneity of the US Black women’s population is crucial in measuring and monitoring progress toward eliminating health disparities and helping tailor strategies, interventions, and programs aimed at reducing disparities in HIV diagnoses.

Although disparities in HIV diagnoses among Black women have been documented,^2,4–6 many studies have compared Black women with White and Hispanic women regardless of place of birth.^2,5 Few studies have examined differences among groups of Black women by world region of birth (e.g., Africa and the Caribbean).^4,7 Because HIV is not evenly distributed among US- and non–US-born Black women,⁴ categorizing all Black women into 1 racial group for tracking progress in reducing disparities in diagnoses can mask the unequal progress in reducing HIV among certain groups of Black women. Cases among non–US-born Black women are often not separated from US-born Black women in surveillance analyses. Consequently, the surveillance data used to inform the development and planning of HIV-prevention policies and programs may not address the needs of non–US-born Black women.

We examined changes in absolute and relative disparities among US- and non–US-born Black women to determine differences in HIV diagnosis disparities. We further categorized non–US-born women by world region of birth and assessed disparities among Caribbean- and Africa-born Black women. We used HIV diagnosis rates among groups of Black women (US-, non–US-, Caribbean-, and Africa-born) to determine whether absolute and relative disparity were equally distributed.

METHODS

We analyzed data reported to the Centers for Disease Control and Prevention (CDC) from the United States and its 6 dependent areas (American Samoa, Guam, Northern Mariana Islands, Puerto Rico, the Republic of Palau, and the US Virgin Islands) for Black and White women aged 18 years or older with HIV diagnosed during 2008 to 2016. The CDC collects data through the National HIV Surveillance System in collaboration with state and local health departments. Laboratories, physicians, hospitals, and other health care providers report persons with diagnosed HIV infection to local and state health departments, which transmit data to CDC without names or other personally identifying information. HIV diagnoses that have been reported to the CDC are estimated to account for 85% of all HIV infections in the United States.⁸ Information is collected and reported regarding demographic and clinical characteristics, including HIV risk factors and country of birth. Country of birth is determined by health department personnel conducting active surveillance and accessing medical records. Information regarding immigration status, date of entry into the United States, and country where HIV infection was acquired are not reported to the CDC.⁹

We categorized women born in the United States or its 6 dependent areas as US-born and women born outside the United States or its 6 dependencies as non–US-born. For geographic analyses, we grouped countries of birth (US-born and non–US-born) and world region of birth (Africa and the Caribbean) by using the United Nations’ Demographic Yearbook.¹⁰ We used data reported to the CDC through December 2017 for the analysis. Because of delays in reporting, a minimum of 12 months’ reporting delay is required from the latest data year (2016) when analyzing trends.

We calculated annual HIV diagnosis rates during 2008 to 2016 for groups of White and Black women using the following categories: US-born, non–US born, and total. We calculated rates by using the annual numbers of HIV diagnoses as numerators and age, gender, race/ethnicity, and nativity data from the US Census Bureau’s American Community Survey as denominators.¹¹ To examine temporal trends, we used a generalized linear model to determine estimated annual percent changes (EAPCs) in HIV diagnosis rates for 2008 to 2016.¹² We fitted separate models for different population groups. We determined the significance of a trend by whether the 95% confidence interval (CI) for the EAPC included 0. We completed additional analyses for non–US-born Black women who were born in Africa or the Caribbean because these 2 groups comprise the majority of cases among non–US-born Black women. We analyzed data by using SAS version 9.4 (SAS Institute Inc., Cary, NC).

We assessed disparities in HIV diagnosis rates by measuring both the absolute and relative disparities for selected groups of women, using the rate for all US White (total White) women as the referent group. Although non–US-born White women had the lowest HIV diagnosis rates, the number of HIV cases diagnosed for this group was relatively small and therefore could not be used as the referent group. An absolute measure of disparity in diagnosis rates is the absolute arithmetic difference between a group’s diagnosis rate and the diagnosis rate of the referent group. If R_i is the diagnosis rate for the ith group and R_r is the diagnosis rate for the referent group, the absolute disparity in diagnosis rate between the ith group and the referent group is given by R_i – R_r. The relative measure of disparity in diagnosis rates between the ith group and the referent group is the disparity ratio . We did not conduct statistical tests of significance of observed differences in HIV diagnostic rates and disparity measures because SEs of those differences were unavailable and computing those SEs would have required unreasonable assumptions about the correct theoretical sampling distribution. However, we calculated the percent change in the absolute and relative disparity values from 2008 through 2016 to assess change over time.

RESULTS

During 2008 to 2016, 10 531 White women and 39 333 Black women with complete country of birth information received an HIV diagnosis in the United States and its 6 dependent areas. Of these, 426 (4.0%) White women and 8423 (21.4%) Black women were non–US-born. Of 8423 non–US-born Black women, 5216 (61.9%) had been born in Africa and 2857 (33.9%) had been born in the Caribbean. The percentage of women with missing country of birth information was similar for Black (18.3%) and White (18.8%) women (data not shown).

Estimated Annual Percent Changes

Table 1 presents annual HIV diagnosis rates and EAPCs. During 2008 to 2016, the HIV diagnosis rate declined for all White women from 1.7 per 100 000 to 1.1 per 100 000 population (EAPC = –5.6; CI = –7.4, –3.9; P ≤ .001) and for all Black women from 42.7 per 100 000 to 20.4 per 100 000 population (EAPC = –9.6; CI = –10.4, –8.7; P ≤ .001). Among both White and Black women, rates of HIV diagnoses declined for US- and non–US-born women, with the largest decline among US-born Black women (from 39.8/100 000 to 15.8/100 000 population; EAPC = –11.5; CI = –12.0, –10.9; P ≤ .001).

TABLE 1—

HIV Diagnosis Rates Among Women Aged ≥ 18 Years: National HIV Surveillance System, United States, 2008–2016

	HIV Diagnosis Ratea									2008–2016
Characteristic	2008	2009	2010	2011	2012	2013	2014	2015	2016	EAPC (95% CI)	P
White
US-born	1.9	1.5	1.4	1.4	1.2	1.2	1.2	1.2	1.2	−5.7 (−7.4, −3.9)	≤ .001
Non–US-born	0.6	0.5	0.6	0.5	0.4	0.4	0.5	0.5	0.5	−3.0 (−5.8, −0.2)	.035
Total (all White)	1.7	1.4	1.3	1.3	1.2	1.1	1.1	1.1	1.1	−5.6 (−7.4, −3.9)	≤ .001
Black
US-born	39.8	34.3	29.7	26.8	24.0	20.6	18.6	16.9	15.8	−11.5 (−12.0, −10.9)	≤ .001
Non–US-born	67.5	59.2	61.7	52.6	50.5	51.4	55.0	47.8	54.4	−3.1 (−4.8, −1.4)	≤ .001
Total (all Black)	42.7	36.8	33.1	29.6	26.9	24.0	22.6	20.5	20.4	−9.6 (−10.4, −8.7)	≤ .001
Africa-born	134.6	118.5	110.0	95.9	98.2	101.4	102.9	88.1	92.1	−4.4 (−6.0, −2.7)	≤ .001
Caribbean-born	45.6	36.4	43.9	35.7	31.1	29.5	32.1	26.1	35.5	−4.9 (−7.8, −2.0)	.001

Note. CI = confidence interval; EAPC = estimated annual percent change.

^aPer 100 000 population.

However, the decline in rates for non–US-born Black women was smaller (from 67.5/100 000 to 54.4/100 000 population; EAPC = –3.1; CI = –4.8, –1.4; P ≤ .001) than was that for US-born Black women. The HIV diagnosis rates for Africa-born Black women declined from 134.6 per 100 000 to 92.1 per 100 000 population (EAPC = –4.4; CI = –6.0, –2.7; P ≤ .001). The rates for Caribbean-born Black women declined from 45.6 per 100 000 to 35.5 per 100 000 population (EAPC = –4.9; CI = –7.8, –2.0; P = .001).

Absolute Disparities

Absolute disparities in HIV diagnosis rates between groups of Black women compared with all US White women declined during 2008 to 2016 (Table 2). The absolute disparity in HIV diagnosis rates for US-born Black women declined from 38.1 in 2008 to 14.7 in 2016 (61% decrease), whereas the absolute disparity in HIV diagnosis rates for non–US-born Black women declined from 65.8 in 2008 to 53.3 in 2016 (19% decrease). The absolute disparity in HIV diagnosis rates for Africa-born Black women declined from 132.9 in 2008 to 91.0 in 2016 (31% decrease; Table 2).

TABLE 2—

Disparities in HIV Diagnoses Among Black Women Aged ≥ 18 Years: National HIV Surveillance System, United States, 2008–2016

Characteristic	2008	2009	2010	2011	2012	2013	2014	2015	2016	Percent Change, 2008–2016
Rate differences (absolute disparity)
US-born Black	38.1	32.8	28.4	25.5	22.9	19.5	17.5	15.7	14.7	−61
Non–US-born Black	65.8	57.7	60.3	51.4	49.3	50.3	53.8	46.7	53.3	−19
Total (all Black)	40.9	35.4	31.8	28.3	25.8	22.9	21.5	19.4	19.3	−53
Africa-born Black	132.9	117.0	108.7	94.7	97.1	100.3	101.8	87.0	91.0	−31
Caribbean-born Black	43.8	35.0	42.6	34.5	30.0	28.5	31.0	25.0	34.4	−21
Rate ratios (relative disparity)
US-born Black	22.9	23.6	22.6	21.1	20.7	18.9	16.4	15.1	14.5	−37
Non–US-born Black	38.8	40.8	47.0	41.4	43.5	47.1	48.5	42.7	50.0	29
Total (all Black)	24.5	25.4	25.2	23.2	23.2	22.0	20.0	18.3	18.7	−24
Africa-born Black	77.3	81.8	83.8	75.4	84.7	92.9	90.7	78.7	84.6	9
Caribbean-born Black	26.2	25.1	33.4	28.1	26.8	27.1	28.3	23.3	32.6	25

Note. Referent group was all US White (total White) women.

Relative Disparities

The relative disparity in HIV diagnosis rates between US-born Black women and all US White women declined from 22.9 in 2008 to 14.5 in 2016 (37% decrease; Table 2). By contrast, an increase occurred in relative disparities in diagnosis rates for non–US-, Caribbean-, and Africa-born Black women. The relative disparity in HIV diagnosis rates increased from 38.8 in 2008 to 50.0 in 2016 (29% increase) for all non–US-born Black women. The relative disparity in rates for Caribbean-born Black women increased from 26.2 in 2008 to 32.6 in 2016 (25% increase), and it increased from 77.3 in 2008 to 84.6 in 2016 (9% increase) for Africa-born Black women (Table 2).

DISCUSSION

We found differences in absolute and relative disparity values and trends among US-born and non–US-born Black women. This difference would not have been revealed if we had used all Black women as a single analysis category. Because HIV diagnosis rates declined from 2008 to 2016 for all groups of Black women and the reference group of all US-born White women, absolute disparities might have declined across the groups studied (Figure 1). The relative disparity, however, only declined for all Black and US-born Black women and increased for the Caribbean-, Africa-, and all non–US-born Black women during 2008 to 2016. The decrease in the absolute disparity in HIV diagnosis rates for the Caribbean-, Africa-, and all non–US-born groups of Black women is not large enough to reduce relative disparity for these groups.¹³

FIGURE 1—

Disparities in HIV Diagnoses Among Black Women Aged ≥ 18 Years by (a) Rate Differences (Absolute Disparity) and (b) Rate Ratios (Relative Disparity): United States, 2008–2016

Note. The referent category was all White women.

The US Black population has become increasingly heterogeneous in recent years, with a 135% increase in African immigrants since 2000.¹⁴ The HIV diagnosis rate and the disparities identified among Africa-born women bears a resemblance to the HIV epidemic profiles of certain African counties from which the majority of the Black women immigrated.^4,6,7 At the end of 2013, 80% of the 16 million women aged 15 years or older with diagnosed HIV had lived in sub-Saharan Africa,¹⁵ where pronounced gender inequalities in HIV infection have been reported.¹⁶ The majority of Africa-born women with diagnosed HIV residing in the United States were from this region, according to a recent study.⁴ Furthermore, most of these women may be living in worse poverty than are other immigrant women. Those from sub-Saharan Africa were more likely to live in poverty than were other immigrants or US-born persons in 2015.¹⁷

Our analysis is subject to certain limitations. First, these data reflect only cases of HIV infection reported to the CDC and might not reflect all persons with HIV infection residing in the United States. HIV surveillance data might not be representative of all persons with HIV, because not all infected persons have been (1) tested, (2) tested at a time when their infection could be detected and diagnosed, or (3) reported to the surveillance system. Second, country of birth was not collected consistently across all jurisdictions, and we excluded cases among women with an unknown place of birth who received a diagnosis of HIV infection from the analysis. Finally, differences in testing patterns among select groups of Black women might have contributed to differences in diagnosis and disparity rates. For example, studies have reported that differences in HIV testing patterns exist by nativity among Blacks, with higher testing among US-born Blacks than among non–US-born Blacks.^7,18 Our estimates might underrepresent the diagnosis rates for the non–US-born Black population; however, if the rates for non–US-born Blacks are underrepresented, the disparities are likely larger than we have reported.

One of the strategic goals of the CDC’s Division of HIV/AIDS Prevention is reducing HIV-related disparities and health inequalities.¹⁹ To achieve this goal, the CDC pursues a high-impact prevention approach for directing efforts to the communities where HIV is most heavily concentrated.²⁰ Achieving national HIV-prevention goals requires actively using data to monitor and assess progress and then refining and improving prevention programs as needed in the context for the specific populations at highest risk.⁵ Understanding the magnitude of disparities in HIV diagnosis and developing disparity-reducing approaches can be guided by an analysis of absolute and relative disparity measures within groups at high risk for HIV infection, including those we have discussed. Future studies in HIV prevention and control should consider examining within-group variations in absolute and relative disparity measures to aid public health’s understanding of the differences among groups and to assist with tailoring strategies, interventions, and programs for reducing disparities in HIV diagnoses.