In late November 1999, a TV producer called me about an alarming report that 44,000 to 98,000 Americans were being killed each year by preventable errors in hospitals, and another 1 million were being injured. Could that be true? Based on my research, I replied, the estimate seemed low.

The “To Err is Human” report from the Institute of Medicine has been called a “seminal moment” in the patient safety fight. The public furor sparked by the group’s assertion that medical mistakes were deadlier than breast cancer, auto accidents, or AIDS prompted new laws, as well as vows to meet the Institute of Medicine’s goal of cutting medical errors in half in five years.

Twenty years after the report’s release, how safe is our medical care?

 …