Optimizing the Timing of HIV Screening as Part of Routine Medical Care

The Potential Impact of One-Time Routine HIV Screening on Prevention and Clinical Outcomes in the United States: A Model-Based Analysis

BACKGROUND

US guidelines recommend routine human immunodeficiency virus (HIV) screening of all adults and adolescents at least once. The population-level impact of this strategy is unclear and will vary across the country.

METHODS

We constructed a static linear model to estimate the optimal ages and incremental impact of adding 1-time routine HIV screening to risk-based, prenatal, symptom-based, and partner notification testing. Using surveillance data and published studies, we parameterized the model at the national level and for 2 settings representing subnational variability in the rates and distribution of infection: King County, WA and Philadelphia County, PA. Screening strategies were evaluated in terms of the percent of tests that result in new diagnoses (test positivity), cumulative person-years of undiagnosed infection, and the number of symptomatic HIV/acquired immune deficiency syndrome cases.

RESULTS

Depending on the frequency of risk-based screening, routine screening test positivity was maximized at ages 30 to 34 years in the national model. The optimal age for routine screening was higher in a setting with a lower proportion of cases among men who have sex with men. Across settings, routine screening resulted in incremental reductions of 3% to 8% in years of undiagnosed infection and 3% to 11% in symptomatic cases, compared with reductions of 36% to 69% and 41% to 76% attributable to risk-based screening.

CONCLUSIONS

Although routine HIV screening may contribute meaningfully to increased case detection in persons not captured by targeted testing programs in some settings, this strategy will have a limited impact on population-level outcomes. Our findings highlight the importance of a multipronged testing strategy with continued investment in risk-based screening programs.