Spillover Effects From A Consumer-Based Intervention To Increase High-Value Preventive Care.

Increasing the use of high-value medical services and reducing the use of services with little or no clinical value are key goals for efficient health systems. Yet encouraging the use of high-value services may unintentionally affect the use of low-value services. We examined the likelihood of high- and low-value service use in the first two years after an insurance benefit change in 2011 for one state's employees that promoted use of high-value preventive services. In the intervention group, compared to a control sample with stable benefit plans, in year 1 the likelihood of high-value service use increased 11.0 percentage points, and the likelihood of low-value service use increased 7.9 percentage points. For that year we associated 74 percent of the increase in high-value services and 57 percent of the increase in low-value services with greater use of preventive visits. Our results imply that interventions aimed at increasing receipt of high-value preventive services can cause spillovers to low-value services and should include deterrents to low-value care as implemented in later years of this program.