Spending and quality after three years of Medicare's bundled payments for medical conditions: quasi-experimental difference-in-differences study.

In this longer term evaluation of a large national programme on medical bundled payments in the US, participation in bundles for four common medical conditions was associated with savings at three years. The savings were generated by practice changes that decreased use of high intensity care after hospital discharge without affecting quality, which also suggests that bundles for medical conditions could require multiple years before changes in savings and practice emerge.