Incentives Versus Defaults: Cost-Effectiveness of Behavioral Approaches for HIV Screening.

Many HIV positive individuals are still undiagnosed, which has led health systems to try many approaches to expand HIV testing. In a randomized controlled trial, we found that behavioral economics interventions (opt-out testing and financial incentives) each improved HIV testing rates and these approaches are being implemented by several hospital systems. However, it is unclear if these strategies are cost-effective. We quantified the cost-effectiveness of different behavioral approaches to HIV screening-opt-out testing, financial incentives, and their combination-in terms of cost per new HIV diagnosis and infections averted. We estimated the incremental number of new HIV diagnoses and program costs using a mathematical screening model, and infections averted using and HIV transmission model. We used a 1-year time horizon and a hospital perspective. Switching from opt-into opt-out results in 39 additional diagnoses (56% increase) after 1-year at a cost of $3807 per new diagnosis. Switching from no incentive to a $1, $5, or $10 incentive adds 14, 13, and 28 new diagnoses (20, 19, and 41% increases) at a cost of $11,050, $17,984, and $15,298 per new diagnosis, respectively. Layering on financial incentives to opt-out testing enhances program effectiveness, though at a greater marginal cost per diagnosis. We found a similar pattern for infections averted. This is one of the first cost-effectiveness analyses of behavioral economics interventions in public health. Changing the choice architecture from opt-into opt-out and giving financial incentives for testing are both cost-effective in terms of detecting HIV and reducing transmission. For hospitals interested in increasing HIV screening rates, changing the choice architecture is an efficient strategy and more efficient than incentives.