Return on public health investment: CDC's Expanded HIV Testing Initiative.

Background: Over a 3-year period, the Centers for Disease Control and Prevention invested $102.3 million in a large-scale HIV testing program, the Expanded HIV Testing Initiative for populations disproportionally affected by HIV. Policy makers, who must optimize public health given a set budget, are interested in the financial return on investment (ROI) of large-scale HIV testing.

Methods: We conducted an ROI analysis using expenditure and outcome data from the program. A health system perspective was used that included all program expenditures including medical costs of treating newly diagnosed patients. We incorporated benefits of HIV transmissions averted from persons diagnosed of their infection through the Initiative compared with when, on average, those persons would have been diagnosed without the Initiative (3 years later in the base case). HIV transmissions were derived from a published mathematical model of HIV transmission. In sensitivity analysis, we tested the effect of 1-year to 5-year alternate testing intervals and differences in the prevalence of undiagnosed HIV infection.

Results: Under the Initiative, 2.7 million persons were tested for HIV, there was a newly diagnosed HIV positivity rate of 0.7%, and an estimated 3381 HIV infections were averted. It achieved a return of $1.95 for every dollar invested. ROI ranged from $1.46 to $2.01 for alternative testing intervals of 1-5 years and remained above $1 (positive return on investment) with a prevalence of undiagnosed HIV infection as low as 0.12%.

Conclusions: The expanded testing Initiative yielded ROI values of >$1 under a broad range of sensitivity analyses and provides further support for large-scale HIV testing programs.