Data Methods

Learn more about the data that informs AHEAD.

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HIV viral suppression indicator icon HIV viral suppression

HIV viral suppression was defined as a viral load result of <200 copies/mL at the most recent viral load test during the year of interest. The cutoff value of <200 copies/mL was based on the following definition of viral failure: viral load of ≥ 200 copies/mL. If multiple viral load tests were performed during the same month and could therefore qualify as “most recent,” the highest viral load (most severe) was selected. If the numerical result was missing or the result was a logarithmic value, the interpretation of the result (e.g., below limit) was used to determine viral suppression. Viral failure may indicate lack of adherence to ART.

Formula for the Viral Suppression indicator


HIV viral suppression for a given year was measured for persons aged ≥13 years and living with HIV infection that had been diagnosed by the beginning of the previous year and were alive at the end of the given year. As an example, viral suppression for 2017 was measured:

  • Among persons whose infection was diagnosed by year-end 2016,
  • Persons who resided in any of the 42 jurisdictions as of their most recent known address during 2017, and
  • Persons who were alive at year-end 2017.

The 42 jurisdictions are those that reported complete CD4 and viral load test results to CDC (HIV Surveillance Report Supplemental Report 2020 Volume 25, Number 2).

HIV viral suppression is available only for states with complete laboratory data (at least 95% of laboratory results are reported to the surveillance programs and transmitted to CDC). For the baseline year 2017, HIV viral suppression was available for the following 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. In 2019, the number of jurisdictions with complete laboratory data increased to 45.

Nevertheless, completeness of reporting varied among states and local jurisdictions.

  • EHE areas without laws requiring complete reporting:
    • Idaho
    • New Jersey
  • EHE areas with incomplete reporting:
    • Kansas
    • Kentucky
    • Pennsylvania (excluding Philadelphia)
    • Vermont
    • Puerto Rico

For more information on the surveillance measure of HIV viral suppression, please refer to the HIV Surveillance Report Supplemental Report Volume 26, Number 2

Estimates should also be interpreted with caution for EHE areas (including Phase 1 EHE states, EHE jurisdictions, or states that contain EHE jurisdictions) with incomplete ascertainment of deaths. Areas with incomplete ascertainment of deaths in 2019 were Kansas, Massachusetts, Mississippi, Nevada, North Dakota, and Vermont.