Adults with complex health care needs who are engaged in their care—whether by self-managing their condition or participating in treatment decisions—report fewer medical errors, rate their care more highly, and hold more positive views of the health system, according to an analysis of findings from an 11-nation survey conducted by The Commonwealth Fund. But the level of patient engagement by providers across countries varies widely, according to the new study (Journal of Ambulatory Care Management, April/June 2012).