Data for the years 2021 & 2022 are preliminary. Due to the impact of the COVID-19 pandemic, data for the year 2020 should be interpreted with caution. Visit coronavirus.gov for the latest Coronavirus Disease (COVID-19) updates.
COVID-19 disruptions in HIV, diagnosis, care and reporting of deaths during 2020 have also made incidence, prevalence, and knowledge of status estimates derived from a CD4-based model, unreliable. Therefore, the HIV surveillance supplemental report Estimated HIV Incidence and Prevalence in the U.S., which provides data on estimated incidence, prevalence, and knowledge of status in the U.S., was not published by CDC this year.

Baseline Data | AHEAD

Glossary

Learn more about the terminology used in the Ending the HIV Epidemic in the U.S. (EHE) initiative.

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Click on a term to view its definition.

Baseline Data

Baseline data are the initial data collected prior to the start of an intervention. These data serve as a point of reference as subsequent data are collected and compared against the baseline data to measure progress towards intervention goals. AHEAD uses data from 2017 as the baseline.