John James has dedicated himself to improving hospital safety. His teenage son died after what James says was a series of hospital errors.          

"We got humans here. They make mistakes,” said James. “The real question is ‘are they making too many mistakes and are they learning from the ones they make?’ And my answer is they're not learning as well as they could be."

The Journal of Patient Safety published James' analysis, which estimates 440,000 people a year die after suffering medical errors in hospitals. James says it's the third biggest cause of death after heart disease and cancer.  Consumer Reports has also studied hospital safety and has rated more than 2500 hospitals on how safe they are.

Consumer Reports mortality ratings are based on how likely patients are to die within 30 days of being admitted for a heart attack, heart failure or pneumonia.  And they consider how often surgery patients with serious treatable complications die in the hospital.

"Although this data is from people 65 and older, it's a good indication of a hospital's attention to safety,” said Dr. John Santa.  “And we find the chance of dying is much higher in some hospitals than others.”

Consumer Reports hopes that by putting a spotlight on safety, hospitals will do a better job preventing hospital errors.  Consumer Reports advises people to be an informed patient and have a friend or family member with you as much as possible.