Data Methods

Learn more about the data that informs AHEAD.

Linkage to HIV medical care indicator icon Linkage to HIV medical care

The linkage to HIV medical care indicator is measured by documentation of at least 1 CD4 or viral load test performed ≤1 month after HIV diagnosis among persons aged ≥13 years. This indicator is only available for states with complete laboratory data (at least 95% of laboratory results are reported to the surveillance programs and transmitted to CDC). Linkage to care data by jurisdiction are based on residence at time of diagnosis of HIV infection. Totals for linkage to care includes persons whose infection was attributed to hemophilia, blood transfusion, or perinatal risk exposure or whose risk was not reported or not identified. Data for these groups are not displayed because the numbers are too small to be meangingful.

For the baseline year 2017, linkage to HIV medical care was available for 41 states and Washington, District of Columbia: Alabama, Alaska, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, and Wyoming. There are 41 areas with complete lab reporting for 2018 however, the composition of the states changed. In 2018, linkage was available for Nevada but not available for Connecticut.

Nevertheless, completeness of reporting varied among states and local jurisdictions. Linkage to care data are not provided for jurisdictions that do not have laws requiring reporting of all CD4 and viral loads, or that have incomplete reporting of laboratory data to CDC.

  • EHE areas without laws requiring complete reporting:
    • Idaho
    • New Jersey
    • Pennsylvania (excluding Philadelphia)
  • EHE areas with incomplete reporting:
    • Arizona
    • Arkansas
    • Connecticut (for 2018 only)
    • Kansas
    • Kentucky
    • Nevada (for 2017 only)
    • Vermont
    • Puerto Rico

Linkage to care data by quarter will be calculated for the cumulative number of persons who received an HIV diagnosis by the quarter of interest for the specified calendar year. A 3-month reporting lag is required for calculating linkage to care due to known delays in reporting of laboratory data (e.g., linkage to care through March 2020 is calculated using data reported to CDC’s National HIV Surveillance System through June 2020). Data presented by quarter are preliminary.

More information can be found at: HIV Surveillance Report Supplemental Report Volume 25, Number 1.