DATA METHODS

DATA RELEASE

To permit the display of HIV care continuum indicators, data were obtained through release agreements from the following health departments overseeing HIV surveillance:

City:
1. Atlanta (Georgia Department of Public Health, Division of Health Protection, Epidemiology Program, HIV/AIDS Epidemiology Section)
2. Chicago (Chicago Department of Public Health, Surveillance, Research, and Evaluation Branch, Office of AIDS)
3. Dallas (Texas Department of State Health Services, HIV/STD Prevention and Care Branch)
4. New Orleans (Louisiana Department of Health and Hospitals, Office of Public Health, STD/HIV Program)
5. New York (New York Department of Health and Mental Hygiene, HIV Epidemiology and Field Services Program)
6. Philadelphia (Philadelphia Department of Public Health, AIDS Activities Coordinating Office)
7. San Francisco (San Francisco Department of Public Health, HIV/Epidemiology Section)
8. Washington, D.C (District of Columbia Department of Health, HIV/AIDS, Hepatitis, STD, and TB Administration)
State:
1. Illinois (Illinois Department of Public Health Office of Health Protection, HIV Surveillance Unit)
2. Texas (Texas Department of State Health Services, HIV/STD Prevention and Care Branch)

DATA AND DEFINITIONS:

HIVContinuum allows viewers to look at county/ZIP-code HIV surveillance data by race/ethnicity, sex and age groups. Maps for cities display data by ZIP-code and maps for states display data by county. For New HIV Diagnoses, Late HIV Diagnoses, and Linkage to HIV Care indicators, 5-year cumulative counts/risks were reported using the residence at the time of HIV diagnosis. For indicators of Engagement in HIV Care, and Viral Suppression for those Engaged and Newly Diagnosed, single year data were reported using most recent known address. The black and white race groups are non-Hispanic, and the Hispanic/Latino ethnicity is inclusive of all races. Sex was defined as “sex at birth.” Cases were assigned to age groups based on age at the time of HIV diagnosis for the first three indicators and current age was used for the last three indicators. Caution should be exercised when viewing and interpreting the county/ZIP-code maps because the scales change across the different breakdowns; the correct scale is always displayed adjacent to the map, regardless of the breakdown.

The definitions of the HIV care continuum indicators used on this website are:

New HIV Diagnoses: This value represents the 5-year (2010-2014) risk of new HIV diagnosis among the adult/adolescent population within each county/ZIP-code. This indicator is not a rate of new diagnosis. The numerator is the number of new HIV diagnoses between 2010-2014, inclusive, among those aged 13 years and older at diagnosis. The denominator for this proportion is the 2010 census population aged 13 years and older obtained from the U.S. Census Bureau.
Late HIV Diagnoses: This value represents the proportion of adults/adolescents diagnosed with HIV between 2010-2014 within each county/ZIP-code who were diagnosed late in the HIV disease process. The numerator is the number of individuals aged 13 years and older at HIV diagnosis, diagnosed between 2010 and 2014, who were diagnosed with immunologic or clinical AIDS (new CDC classification as A3, B3, or C1-C3) within 3 months of initial HIV diagnosis. The denominator is the number of individuals aged 13 years and older who were newly diagnosed with HIV from 2010-2014.
Linkage to HIV Care: This value represents the proportion of adults/adolescents diagnosed with HIV between 2010-2014 within each county/ZIP-code who were linked to HIV care within 1 month of their diagnosis, excluding same day linkages. The numerator is the number of individuals aged 13 years and older at HIV diagnosis, who were diagnosed from 2010-2014, and had a CD4 or HIV viral load (VL) count within 1 month of their initial HIV diagnosis. The denominator is the number of individuals aged 13 years and older who were newly diagnosed with HIV from 2010-2014.
Engagement in HIV Care: This value represents the proportion of adults/adolescents living with diagnosed HIV infection in 2015, excluding those newly diagnosed in 2015, who were engaged in care in 2015. The numerator is the number of individuals aged 13 years and older in 2015, who are living with diagnosed HIV infection in 2015 and excluding those newly diagnosed in 2015, who had a most recent CD4 count or HIV VL test in 2015, excluding CD4/VL concurrent with diagnosis and first ever CD4/VL not concurrent with diagnosis (i.e., not the “linkage CD4/VL”). The denominator is the number of individuals aged 13 years and older in 2015, living with diagnosed HIV in 2015 and excluding those newly diagnosed in 2015, and who had at least one previous CD4/VL not concurrent with diagnosis (i.e. linked to care).
HIV Viral Load Suppression Among Those Living with Diagnosed HIV Infection This value represents the proportion of adults/adolescents living with diagnosed HIV infection in 2015, excluding those newly diagnosed in 2015, who had a suppressed HIV VL in 2015. The numerator is the number of individuals aged 13 years and older in 2015 living with diagnosed HIV infection in 2015, excluding those newly diagnosed in 2015 who had a most recent reported HIV VL count <200 copies />ml in 2015. The denominator is the number of individuals aged 13 years and older in 2015, living with diagnosed HIV infection in 2015. and excluding those newly diagnosed in 2015.
HIV Viral Load Suppression Among Those Engaged in Care This value represents the proportion of adults/adolescents living with diagnosed HIV infection in 2015, excluding those newly diagnosed in 2015, who had a suppressed HIV VL in 2015 and engaged in care. The numerator is the number of individuals aged 13 years and older in 2015, living with diagnosed HIV infection in 2015 and excluding those newly diagnosed in 2015, who had a most recent reported HIV VL count <200 copies />ml in 2015. The denominator is the number of individuals aged 13 years and older in 2015, living with diagnosed HIV infection in 2015 and excluding those newly diagnosed in 2015, who had a most recent CD4 count or HIV VL test in 2015, excluding CD4/VL concurrent with diagnosis and first ever CD4/VL not concurrent with diagnosis.

For county/ZIP-codes that house correctional institutions, caution should be exercised when interpreting the data as these statistics are inclusive of institutional populations, and their inclusion may artificially inflate the actual case counts and risks of a county/ZIP-code when an institution is housed in it.

As is standard in the display of health statistics, data generated from a numerator less than 12 are considered unstable and should be interpreted with caution. If a specific county/ZIP-code meets the criterion for instability, a message in the balloon will appear when you place your mouse cursor over the county/ZIP-code noting that the reported value is unstable.

HIV Continuum does not display new diagnoses data when the numerator is less than 5 for county/ZIP-code and/or the denominator (number of people in the county/ZIP-code in that population group) is less than 500 for ZIP-code or less than 100 for county. For all other indicators, data are suppressed when the numerator is than 5, or for Philadelphia, Dallas, and Texas, are the only exceptions where the data are suppressed when the numerator is less than 6. Counties/ZIP-codes appear in a shade of gray when one or both conditions for suppression are met (see footnote below map scale).

Each public health department defined the city-level geographic area (e.g., ZIP-codes) in their jurisdiction for which they desired to display data on HIVContinuum. For details regarding each jurisdiction’s assignment of ZIP-codes to cases missing an address at diagnosis, or to other data-related issues, see the Data Caveats table below. Denominators used to calculate new diagnosis data for ZIP-codes and counties were obtained from the U.S. Census Bureau’s 2010 census of ZIP-code Tabulation Areas (ZCTAs) and counties.

Data for HIV testing sites were obtained from the Centers for Disease Control and Prevention, National Prevention Information Network as an ongoing data access request. Ryan White HIV/AIDS Medical Care provider data for HIV care sites were obtained from the Health Resources and Services Administration, HIV/AIDS Bureau as an annual data request.

Range intervals for new diagnosis data for each city/state were defined using the overall new diagnosis data for each city/state. New diagnosis data stratified by age, race, and sex within each city/state are displayed using these ranges. The five remaining indicators are displayed using pre-defined ranges that are not specific to each city/state. For linkage to HIV care, we defined the best category (lightest color) at 85% or greater, and for engagement in HIV care, we defined the best category (lightest color) at 90% or greater, as these meet or exceed the 2020 target in the US National HIV/AIDS Strategy. For late diagnosis, we defined the best category as 10% or less derived from the National HIV/AIDS Strategy target of increasing awareness of HIV status to more than 90% of those with HIV infection. For viral suppression, we defined the best category of 80% or greater based on the National HIV/AIDS Strategy target of increasing the percentage of persons with diagnosed HIV infection who are virally suppressed.

HIV CARE CONTINUUM INDICATORS ON THE CHART:

Each box in the charts represents the mode (i.e. the most commonly occurring) category for each combination of demographic stratification and HIV care continuum indicator at the county/ZIP-code level. Since ranges for new diagnoses are defined based on the distribution of the overall new diagnosis data within each city/state, each category of overall new diagnoses occurs with the same frequency and the mode of these data cannot be displayed.

The best categories (lightest color) for late diagnosis (≤ 10%), linkage (≥ 85%), engagement (≥ 90%) and viral suppression (≥ 90%) are based on targets in the National HIV/AIDS Strategy. Categories depicted in darker colors represent worsening gaps in achieving these targets.

COMPARABILITY OF DATA ACROSS CITIES:

The case definitions and data systems for new HIV diagnoses and late HIV diagnoses are standard in HIV case surveillance, but standardization for the other indicators used here is still a work-in- progress. In these 8 cities and 2 states, the public health authority requires that all CD4 and HIV VL tests be reported, regardless of the result. Though most of these reports come directly from laboratories, the degree of completeness of reporting and the ability to link laboratory results to diagnosed cases both within and across jurisdictions is not precisely known. Therefore, direct comparisons of these indicators among cities or between states should not be made. The main utility of HIVContinuum is to visualize patterns in the HIV care continuum within each city or state.

Data Caveats

Atlanta: Data reflect HIV cases diagnosed from 2010-2014 and reported through 12/31/16 in zip codes that lie within the Atlanta MSA. Cases missing address or ZIP-code are excluded from the maps.
Chicago: Data reflect cases reported and entered through 9/30/2016. Cases missing address or ZIP-code are excluded from the maps. Homeless cases with addresses of a shelter were assigned to the ZIP-code of the homeless shelter.
Dallas: Data are suppressed when the numerator is less than 6.
New Orleans: New Orleans data represent persons diagnosed with HIV in the City of New Orleans between 2010-2014. Cases missing ZIP-code are excluded from the maps.
New York: Data reflect cases reported through 6/30/2016. Cases missing address or ZIP-code are excluded from the maps. Cases diagnosed in and listing an address of a correctional facility are assigned to the ZIP-code of the correctional facility. Homeless cases with addresses of a shelter are assigned to the ZIP-code of the homeless shelter.
Philadelphia: Data reflect cases reported through 6/30/2016. Data reflect cases from ZIP-codes in Philadelphia county only. Cases missing address or ZIP-code are excluded from the maps. Cases diagnosed in a correctional facility are assigned to the ZIP-code of the correctional facility. Data are suppressed when the numerator is less than 6. Linkage to HIV care includes same day linkage.
San Francisco: San Francisco data are reported through 12/27/2016 for persons diagnosed with HIV in San Francisco between 2010 and 2014 and persons living with diagnosed HIV in San Francisco as of 12/31/2015. Cases missing ZIP code and homeless cases are excluded from the maps. Usual residence was determined for cases diagnosed in a correctional facility. If a usual residence could not be determined, the case would have an unknown San Francisco address because these cases were not assigned the correctional facility address at time of diagnosis.
Washington, DC: Data reflect cases reported through 3/16/2016. Cases with missing address information at diagnosis were not included in this analysis. Cases diagnosed in a correctional facility are assigned to the ZIP-code of the correctional facility. Homeless cases with addresses of a shelter are assigned to the ZIP-code of the homeless shelter.
Illinois: Cases missing address or ZIP-code are excluded from the maps. Cases diagnosed in and listing an address of a correctional facility are assigned to the ZIP-code of the correctional facility. Homeless cases with addresses of a shelter are assigned to the ZIP-code of the homeless shelter. Total, male, and female population denominators include persons aged less than 13.
Texas: Data are suppressed when the numerator is less than 6. Total, male, and female population denominators include persons aged less than 13.