Source: Tammie L. Nelson, MPH, CPH, Epidemiology Manager at the Marion County Public Health Department
Published March 9, 2018
The Marion County Public Health Department’s Ryan White HIV Services Program (RWSP) manages Part A, Minority AIDS Initiative (MAI), and Part C funding to address the needs of people living with HIV (PLWH) in central Indiana, including those out of care or historically underserved or uninsured. The program helps out-of-care clients gain access to points of entry; provides a comprehensive HIV continuum of care; and complies with the National HIV/AIDS Strategy (NHAS).[1]
Viral load suppression is the ultimate measure of health for individuals living with HIV. Comparing HIV care outcomes over time or between groups of PLWH requires evaluation of community viral load (CVL) – an average of all viral load results taken from among PLWH in defined populations. Evaluating CVL is important to identify differences in HIV health outcomes among various populations. CVL analysis assists in identifying disparities in HIV care outcomes. The RWSP has undertaken a clinical quality management project to monitor differences in viral load among PLWH in Central Indiana. This project includes viral load analyses of PLWH in the Ryan White Part A transitional grant area (TGA). TGA counties include: Boone, Brown, Hamilton, Hancock, Hendricks, Johnson, Marion, Morgan, Putnam, and Shelby.
In 2017, 6,050 PLWH resided in the TGA, and health outcomes among these individuals have been improving. The percentage of the TGA’s HIV-positive residents who had suppressed viral loads increased from 50% to 64% during the period 2013-2017. These improved health outcomes were not equitable, however, and it is the goal of this article to identify disparities among PLWH in Central Indiana, arming both medical and supportive care providers with this knowledge so that resources can be focused to serve those who need help the most.
METHODS
Suppressed viral load is defined as a result of less than 200 HIV RNA copies per milliliter (c/mL) of blood, an indication of successful HIV treatment.[2] To identify disparities in viral load suppression among PLWH in the TGA, a retrospective analysis of 2013-2017 HIV surveillance records was conducted. Viral load suppression among those with at least one viral load test was compared by demographic and risk factors using chi-square analysis. Multiple logistic regression was used to evaluate main and interaction effects. A methodology recommended by the Centers for Disease Control and Prevention (CDC)[3] was used to normalize viral load data and tighten confidence intervals for group comparisons using standardized lab results and geometric, rather than arithmetic, means. The rationale for use of geometric mean (GM) is that it helps to normalize viral load distribution, reducing the influence of outlying measurements such as extremely high viral load seen in those newly infected or recently engaged in care. It is important to remember that the GM does not represent a true viral load and is, instead, intended for use only to compare viral load suppression between groups.
RESULTS
Stepwise logistic regression was used to evaluate main effects of, and interactions between first detectable viral load result, retention in care, race/ethnicity, current age, gender, and Ryan White Part A/MAI/C service utilization. All variables met the retention threshold (P<0.3) and were retained in the model; however, only three variables remained significant when examining interaction effects.
Viral suppression at first HIV viral load test was a significant predictor of current viral load suppression. In fact, those who were suppressed at first HIV viral load were only half as likely to have a current viral load above 200 c/mL [OR=0.52; 95% CI: 0.31-0.87].
Being retained in care was the most significant predictor of viral load suppression, however, with those not retained in care experiencing a nearly four-fold increased risk of not being virally suppressed, even when controlling for first viral load result [OR=3.91; 95% CI: 3.26-4.69].
The only other predictor that remained significant among TGA residents was race. Regardless of first HIV viral load result and/or retention in care status, Hispanic/Latinos had 1.5 times the risk of Whites [OR=1.54; 95% CI: 1.08-2.20] and, with even worse outcomes, African Americans were nearly twice as likely to have unsuppressed viral load as their White peers [OR=1.90; 95% CI: 1.54-2.34]. While viral load suppression disparities narrowed during 2013-2017, non-Asian/Pacific Islander minorities consistently fared worse than their peers (Figure 1).
Figure 1: Geometric Mean Viral Load (c/mL) among Indianapolis TGA Residents with at Least One Viral Load Test, by Race/Ethnicity: 2013-2017
KEY FINDINGS & DISCUSSION
Retention in care throughout the year was the most significant predictor of viral load suppression, with those not retained in care found to be nearly four times as likely to have an unsuppressed viral load. It is important to keep PLWH engaged in care and receiving at least two viral load tests per year.
African Americans are almost twice as likely to have an unsuppressed viral load as their peers, regardless of first viral load result and/or retention in care status. Similarly, Hispanic/Latinos have an increased risk of unsuppressed viral load as compared to their White peers. African Americans in the TGA most in need of intervention to decrease viral load were found to be young adult males, 20-34 years of age, and predominately men who have sex with men.
NEXT STEPS
Our data suggest that African Americans and Hispanic/Latinos have higher viral loads than their peers, regardless of first viral load result or retention in care. Efforts to increase retention in care will decrease community viral load overall; however, additional research is needed to determine why African Americans and Hispanic/Latinos experience disparity in viral suppression.
This article is a summary of findings from a comprehensive analysis of viral load results in the Indianapolis TGA. For more information, please contact the author.
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[1] White House Office of National AIDS Policy. (2015). National HIV/AIDS strategy for the United States: Updated to 2020. https://www.aids.gov/federal-resources/national-hiv-aids-strategy/nhas-update.pdf
[2] CDC. (2014). Vital signs: HIV diagnosis, care, and treatment among persons living with HIV – United States, 2011. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6347a5.htm
[3] CDC. (2011). Guidance on community viral load: A family of measures, definitions, and method for calculation. http://www.ct.gov/dph/lib/dph/aids_and_chronic/surveillance/statewide/community_viralload_guidance.pdf