An instrument or instrumental variable is often used in an effort to avoid selection bias in inference about the effects of treatments when treatment choice is based on thoughtful deliberation. Instruments are increasingly used in health outcomes research. An instrument is a haphazard push to...

In this study we examine the impact of a value-based insurance design (V-BID) program implemented between 2010 and 2013 at a large public employer in the state of Oregon. The program substantially increased cost-sharing, specifically copayments and coinsurance, for several healthcare services...