Estimating the probability of diagnosis within 1 year of HIV acquisition

Early diagnosis of HIV is important for the prevention of ongoing transmission and development of HIV-related illness. The purpose of this study is to develop an outcome indicator to monitor the progress in early HIV diagnosis.

Persons diagnosed with HIV in New York City and their first CD4 test results were used to estimate the distribution of HIV diagnosis delay, based on a CD4 count depletion model. The distribution was then used to estimate the probability of diagnosis within 1 year of HIV acquisition, which is the number of cases diagnosed in a given calendar year for which diagnosis occurred within 1 year of acquisition divided by the number of incident cases in that calendar year.

In 2012-2016, the estimated annual probability of diagnosis within 1 year of HIV acquisition in New York City was 43.0% [95% confidence interval (CI): 37.9-48.2%), 42.5% (95% CI: 36.8--48.3%), 42.8% (95% CI: 36.3--49.2%), 42.9% (95% CI: 35.4--50.3%), and 42.2% (95% CI: 33.1--51.2%), respectively.

National and local health jurisdictions should consider using this new outcome indicator, the probability of diagnosis within 1 year of HIV acquisition, to monitor their progress in early HIV diagnosis.