Data for the year 2021 are preliminary. Due to the impact of the COVID-19 pandemic, data for years 2020 and 2021 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.

Knowledge of HIV Status | AHEAD

Data Methods

Learn more about the data that informs AHEAD.

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Knowledge of HIV Status indicator icon Knowledge of HIV Status

Knowledge (or awareness) of HIV-positive status refers to the estimated percentage of HIV+ people who have received an HIV diagnosis. For instance, if an individual tests positive for HIV, but cannot be located to be notified of their test results, they may not know that their status has shifted from HIV- to HIV+. 

Knowledge of HIV status is estimated as the percentage of persons with HIV who have been notified of their diagnosis. It is calculated by dividing the estimated number of persons living with diagnosed infections by the estimated number of persons, both diagnosed and undiagnosed, who are HIV+ within the population (prevalence) for each year. The estimated number of diagnoses and prevalence are derived from the National HIV Surveillance System (NHSS) and includes data for persons aged ≥ 13 years. NHSS data is collected from 50 states, the District of Columbia, and Puerto Rico. 

For more specific information about how knowledge of status is calculated, please refer to the CDC’s HIV Surveillance Report: https://www.cdc.gov/hiv/pdf/library/reports/surveillance/cdc-hiv-surveillance-supplemental-report-vol-26-1.pdf
 

Formula for the Knowledge of Status indicator

 

Completeness of reporting varies among states and local jurisdictions. Estimates should be interpreted with caution for EHE areas (including Phase 1 EHE states, EHE jurisdictions, or states that contain EHE jurisdictions) that do not have laws requiring complete reporting of laboratory data or have incomplete reporting. Currently there are two EHE states (Idaho & New Jersey) that do not have laws requiring complete reporting of laboratory data. Additionally though all jurisdictions report some laboratory data to CDC, there are 5 EHE states (Kansas, Kentucky, Pennsylvania, Puerto Rico, and Vermont) with incomplete reporting based on evaluation of their surveillance data as of 2021. 

Relative Standard Error (RSE)
The relative standard error (RSE) is a measure that shows how large the standard error is relative to the size of the estimated value. It is calculated by dividing the standard error of an estimated value by the estimated value itself, and then multiplied by 100 and expressed as a %. Smaller RSEs are indicative of more reliable results, and larger RSEs are indicative of less reliable results. Estimates with a relative standard error (RSE) of ≥30% do not meet the standard of reliability and are represented in the following way:


•    Estimates with an RSE of 30% - 50% are marked with an asterisk (*), indicating that they should be used with caution.
•    Estimates with an RSE >50 percent are not shown, and are replaced with the phrase “Data N/A due to high relative standard error.”


To reflect model uncertainty, all estimates were rounded to the nearest 100 for estimates of more than 1,000 and to the nearest 10 for estimates of less than 1,000.
More information can be found at: HIV Surveillance Report Supplemental Report Volume 26, Number 1.