Interest in high users of acute care continues to grow as health care organizations look to deliver cost-effective and high-quality care to patients. Since “super-utilizers” of acute care are responsible for disproportionately high health care spending, many programs and interventions have been implemented to reduce medical care use and costs in this population. This article presents a systematic review of the peer-reviewed and grey literature on evaluations of interventions to decrease prehospital and emergency care use among U.S. super-utilizers. Forty-six distinct evaluations were included in the review. The most commonly evaluated intervention was case management. Although a number of interventions reported reductions in prehospital and emergency care utilization and costs, methodological and study design weaknesses—especially regression to the mean—were widespread and call into question reported positive findings. More high-quality research is needed to accurately assess the impact of interventions to reduce prehospital and emergency care use in the super-utilizer population.

Pay for success (PFS) is a type of social impact investing that uses private capital to finance proven prevention programs that help a government reduce public expenditures or achieve greater value. We conducted an analysis of the first eleven PFS projects in the United States to investigate the potential of PFS as a strategy for financing and disseminating interventions aimed at improving population health and health equity. The PFS approach has significant potential for bringing private-sector resources to interventions regarding social determinants of health. Nonetheless, a number of challenges remain, including structuring PFS initiatives so that optimal prevention benefits can be achieved and ensuring that PFS interventions and evaluation designs are based on rigorous research principles. In addition, increased policy attention regarding key PFS payout issues is needed, including the "wrong pockets" problem and legal barriers to using federal Medicaid funds as an investor payout source.

Over the past eight years, there has been an increase in the use of pay for success (PFS) as a financing tool whereby private investors provide initial funding for preventive health and human service interventions. If an independent evaluator deems the interventions successful, investors are repaid by the government. To better understand how PFS is used, we created a global landscape surveillance system to track and analyze data on all PFS projects that have launched through 2017. We focus on the potential for PFS to improve population health by funding interventions that target the social determinants of health. Our findings show that all launched projects to date have implemented interventions aimed at improving the structural and intermediary social determinants of health, primarily in socioeconomically disadvantaged populations. Although there are some challenges associated with PFS, we believe it is a promising tool for financing interventions aimed at social determinants of health in underserved and marginalized populations.