Data Methods – State/County

Below you can learn more about the data methods and sources for the state and county data on AIDSVu. Looking for data methods and sources for ZIP code or census tract data? Click here.

HIV Surveillance Data

The HIV prevalence and new diagnoses data presented on AIDSVu are collected by state and local health departments, and de-duplicated and processed by the U.S. Centers for Disease Control and Prevention (CDC) to meet data quality standards for comparability and reliability. All 50 states, the District of Columbia (DC) and U.S. territories collect comparable confidential, name-based case reports of persons living with an HIV infection diagnosis following standard methods and procedures. Medical providers and other organizations providing HIV testing services are required, by law, to report persons diagnosed with HIV to the state or local health department. Health departments report case data without names to CDC for monitoring of the national HIV epidemic.

All state- and county-level HIV surveillance data for AIDSVu were obtained from CDC’s national HIV surveillance database housed in the Division of HIV Prevention’s HIV Incidence and Case Surveillance Branch. Data were released to AIDSVu by CDC in accordance with HIV-surveillance-specific data re-release agreements between CDC and each state/U.S. territory health department, and in accordance with other CDC data release guidelines. Data reflected on AIDSVu may slightly differ from data obtained directly from state HIV surveillance programs (e.g., on a state health department website or through a data request to a state surveillance program) because states may use analysis criteria that are different from what AIDSVu used (e.g., analyzing data by “current residence” versus “residence at earliest HIV diagnosis”). Further, data on AIDSVu may differ from data obtained directly from the states because AIDSVu’s data source was CDC’s national HIV surveillance database, from which duplicate records are removed. AIDSVu also displays ZIP code and census tract data for a small number of jurisdictions (cities or Metropolitan Statistical Areas). More information about where these data come from and their presentation on AIDSVu can be found here.

All state- and county-level HIV surveillance data displayed on AIDSVu maps and state profile pages are estimated data for persons aged 13 and older living with an HIV infection diagnosis as of December 31, 2010. New diagnoses data are displayed as 4-year cumulative case counts for persons aged 13 and older diagnosed with an HIV infection between January 1, 2008 and December 31, 2011. Estimated numbers resulted from statistical adjustment that accounted for reporting delays and missing risk-factor information, but not for incomplete reporting. Estimates are based upon actual data reported to CDC through June 2012. (See CDC methodology for estimating HIV prevalence.) Residence at time of earliest HIV diagnosis was used in all analyses. Denominators used to calculate 2010 rates for all state and county populations were obtained from the U.S. Census Bureau’s 2010 census. Population denominators are restricted to persons aged 13 and older. There are no counties in Washington, DC, Puerto Rico and Alaska.

Estimated rates of persons living with an HIV diagnosis were calculated per 100,000 population to permit data standardization and comparison. As is standard in the display of health statistics, rates generated from a numerator less than 12 are considered unstable and should be interpreted with caution. To determine if a specific state or county meets this criterion, place the mouse cursor over the state or county and, in the balloon that appears, there will be a message noting that a rate meets this condition, if applicable. For estimated rate ratios by race/ethnicity displayed on state profile pages, white race is the referent group.

Data Suppression and Rate Stability

To protect the privacy of persons living with an HIV infection diagnosis, AIDSVu does not display rates and case counts for states and counties when one or more of the following suppression criteria are met:

  1. Numerator (number of persons living with an HIV infection diagnosis) is less than 5 and/or the denominator (number of people in the state or county in that population group) is less than 100. If the overall county case count is less than 5 and/or the overall county population is less than 100, all data for the county are suppressed.
  2. For breakdowns by sex at the county level, if either the male or female rate and/or case count is suppressed because of the numerator/denominator thresholds mentioned in #1, both sex groups are suppressed to prevent indirect identification.
  3. For breakdowns by age at the county level, if the rate and/or case count for only one age group is suppressed in a county because of the numerator/denominator thresholds mentioned in #1, then the 13-24 age group is also suppressed to prevent indirect identification.  If the 13-24 age group is the only age group suppressed for a county, then the 55+ age group is also suppressed.
  4. If all data for only one county in a state is suppressed, then one additional county is also suppressed, with the additional county selected based on the fact that it has the smallest total population of the remaining counties. In the event there are multiple counties in a state with the exact same total population, the county with the lowest number of HIV cases is also suppressed. In the event there are multiple counties in a state with the same total population and the same total number of HIV cases, then both or all of these counties are suppressed.

States and counties appear white when one or more of these conditions are met. Because rates are not displayed when the numerator is less than 5, the “unstable rate” indicator mentioned above will only display when the numerator is 5 or greater and less than 12.

For 4-year cumulative new diagnoses data, if the overall county case count or overall/race/sex/age state breakdown is less than 20, all data for the county/state are suppressed.

Data Stratification

AIDSVu allows viewers to look at state- and county-level HIV surveillance data at the overall geographic level, and by race/ethnicity, sex, and age groups.  Additionally, AIDSVu displays state- and county-level HIV prevalence data by transmission category. All race groups are non-Hispanic, and the Hispanic/Latino ethnicity is inclusive of all races. Sex is defined as “sex at birth.” Cases were assigned to age groups based on “age at the end of 2010.” Caution should be exercised when viewing and interpreting these different maps because the scales change across the different breakdowns and geographic levels; the correct scale is always displayed to the left of the map regardless of the breakdown.

Data are not displayed at the county level for Asians, Native Hawaiians/Other Pacific Islanders, and American Indians/Alaska Natives because these data do not meet CDC’s criteria for statistical reliability, data quality or confidentiality due to small population denominators and HIV case counts. Race/ethnicity data for Puerto Rico is displayed only by case counts and not by rate.

Displayed Ranges

Range intervals were developed using deciles in SAS analytic software (SAS Institute, Cary, NC). In order to illustrate the variation in rates and case counts, ranges were developed specific to each geographic level (i.e., states or counties), and for each grouping (i.e., overall, and separately by race, by sex and by age group). Thus, for state maps, a total of 12 sets of map scales exist (rate/count by overall/race/sex/age/male transmission category/female transmission category). For county maps, a total of eight sets of map scales exist (rate and count, both by overall/race/sex/age). For state level 4-year cumulative new diagnoses maps, a total of 4 sets of map scales exist (count by overall/race/sex/age). For county-level new diagnoses maps, a total of 1 map scale exists (count by overall). For each scale calculation, we determined deciles by combining the individual rates or counts for all areas with data included on the maps for that geographic level and grouping.

Social determinants of health are displayed on a secondary map and their associated scales were developed using quartiles. Quartiles for each social determinant were determined individually using the same procedure described above. Therefore, there are 10 additional ranges for these data (i.e., five social determinants for both state and county levels).

Corrections Warning

The data displayed on AIDSVu include state and federal correctional populations. Their inclusion may artificially inflate the HIV prevalence rate and case count of counties that house institutions. A correctional warning is displayed in the map hover-over balloon of certain counties when artificial inflation may be present based on predefined criteria.

To determine in which counties the correctional warning should appear, the following process and predefined thresholds were used to categorize counties.

  1. All U.S. counties were categorized by level of urbanization using the National Center for Health Statistics (NCHS) Urban-Rural Classification Scheme.
  2. Federal and state correction populations were obtained for each county from the 2010 U.S. Census.
  3. Within these strata of urbanization, counties are assigned the corrections warning if they had:
    1. Above average HIV prevalence rate (as compared to counties with no correctional population), and
    2. Above average correctional population or above average percent of the population housed in state/federal correctional institutions.

Data Sources

Surveillance Data

Data Element Location on AIDSVu Data Source Anticipated Update Frequency on AIDSVu Website
Estimated Rates and Case Counts of Persons Living with an HIV Diagnosis, State & County Data Maps Centers for Disease Control and Prevention, Division of HIV/AIDS Prevention, HIV Incidence and Case Surveillance Branch; Data Request, October 2012. Annually
Population Denominators for Rate Calculations Maps U.S. Census Bureau. Population Estimates, State Intercensal Estimates (2000-2010) [entire data set]. Published October 2012. Annually
Estimated 4-Year Cumulative Case Counts of Persons Diagnosed with HIV, 2008-2011, State & County Data Maps Centers for Disease Control and Prevention, Division of HIV/AIDS Prevention, HIV Incidence and Case Surveillance Branch; Data Request, January 2013. Annually
Estimated % Late HIV Infection Diagnoses State Profile Pages Centers for Disease Control and Prevention, Division of HIV/AIDS Prevention, HIV Incidence and Case Surveillance Branch; Data Request, October 2012. Annually
Estimated HIV Prevalence Rate Ratios by Race/Ethnicity State Profile Pages Centers for Disease Control and Prevention, Division of HIV/AIDS Prevention, HIV Incidence and Case Surveillance Branch; Data Request, October 2012. Annually
Estimated HIV Prevalence Case Counts and Percentages by Transmission Category, State & County Level Maps; State Profile Pages Centers for Disease Control and Prevention, Division of HIV/AIDS Prevention, HIV Incidence and Case Surveillance Branch; Data Request, October 2012. Annually
STD Case Counts, Rates and National Rankings State Profile Pages Centers for Disease Control and Prevention. Sexually Transmitted Disease Surveillance 2010. Atlanta: U.S. Department of Health and Human Services; 2011 Annually
Age-Adjusted HIV Mortality Rates, 2008-2010. State Profile Pages Centers for Disease Control and Prevention; National Center for Health Statistics. Compressed Mortality File (CMF) on CDC WONDER Online Database, 1999-2010, Series 20, No. 2P, 2013 Annually

HIV Testing, Treatment and Prevention Information, and Federal Funding for HIV/AIDS

Data Element Location on AIDSVu Data Source Anticipated Update Frequency on AIDSVu Website
HIV Testing Sites Maps; HIV Testing Site Locator Centers for Disease Control and Prevention, National Prevention Information Network; Ongoing Data Access Request. Daily
Ryan White HIV/AIDS Medical Care Providers Maps; HIV Treatment Site Locator Health Resources and Services Administration, HIV/AIDS Bureau; Data Request, April 2014. Annually
NIH-Funded HIV Prevention, Vaccine and Treatment Trials Sites Maps National Institutes of Health, National Institute of Allergy and Infectious Diseases, Division of AIDS; Data Request, March 2014. Annually
ADAP Waiting List State Profile Pages National Alliance of State and Territorial AIDS Directors. ADAP Watch. Bi-Monthly
Federal Grant Funding for HIV/AIDS, FY 2010 State Profile Pages Kaiser Family Foundation. State Health Facts. Annually

Social Determinants of Health

Data Element Location on AIDSVu Data Source Anticipated Update Frequency on AIDSVu Website
Poverty (Percent of  population, all ages, living in poverty) – State Level Maps U.S. Census Bureau, Small Area Income and Poverty Estimates, Table 1: 2010 Poverty and Median Income Estimates – States. Release date: 11.2011 Annually
Poverty  (Percent of  population, all ages, living in poverty)- County Level Maps U.S. Census Bureau, Small Area Income and Poverty Estimates, Table 1: 2010 Poverty and Median Income Estimates – Counties. Release date: 11.2011 Annually
Estimated Population and Racial/Ethnic Make-Up of State State Profile Pages U.S. Census Bureau. Population Estimates, Vintage 2011 [entire data set]. Published May 2012 Annually
Educational Attainment (Percent of people over age 25 with at least a high school diploma or equivalent) – State Level Maps U.S. Census Bureau, American Community Survey 1-Year Estimates, 2010, Table C15003: Educational attainment for the population 25 years and over Annually
Educational Attainment (Percent of people over age 25 with at least a high school diploma or equivalent) – County Level Maps U.S. Census Bureau, American Community Survey 5-Year Estimates, 2006-2010, Table DP02: Selected Social Characteristics in the United States Annually
Median Household Income – State Level Maps U.S. Census Bureau, Small Area Income and Poverty Estimates, Table 1: 2010 Poverty and Median Income Estimates – States. Release date: 11.20110 Annually
Median Household Income – County Level Maps U.S. Census Bureau Small Area Income and Poverty Estimates, Table 1: 2010 Poverty and Median Income Estimates – Counties. Release date: 11.2011 Annually
Percent of population under age 65 lacking health insurance – State Level Maps U.S. Census Bureau, Small Area Health Insurance Estimates, 2010: Health Insurance Coverage Status by Age, Race, Hispanic Origin, Sex and Income for Counties and States Annually
Percent of population under age 65 lacking health insurance – County Level Maps U.S. Census Bureau, Small Area Health Insurance Estimates, 2010: Health Insurance Coverage Status by Age, Race, Hispanic Origin, Sex and Income for Counties and States Annually
Gini Coefficient of income inequality – State Level Maps U.S. Census Bureau, American Community Survey 1-Year Estimates, 2010,Table B19083: Gini Index of Income Inequality Annually
Gini Coefficient of income inequality – County Level Maps U.S. Census Bureau, American Community Survey 5-Year Estimates, 2006-2010,Table B19083: Gini Index of Income Inequality Annually

State Health Department Websites

Data Element Location on AIDSVu Data Source Anticipated Update Frequency on AIDSVu Website
State Health Department Websites State Profile Pages State health departments and internet. Annually