First, do no harm-doctors, nurses and clinicians swear by this code of conduct. Yet in hospitals and doctors' offices across the country, errors are made every single day--avoidable, simple mistakes that often cost lives. Inspired by two medical mistakes that not only ended in unnecessary deaths but hit close to home, Dr. Peter Pronovost made it his personal mission to improve patient safety and make preventable deaths a thing of the past, one hospital at a time. Dr. Pronovost began with simple improvements to a common procedure in the ER and ICU units at Johns Hopkins Hospital. Creating an easy five-step checklist based on the most up-to-date research for his fellow doctors and nurses to follow, he hoped that streamlining the procedure itself could slow the rate of infections patients often died from. But what Dr. Pronovost discovered was that doctors and nurses needed more than a checklist: the day-to-day environment needed to be more patient-driven and staff needed to see scientific results in order to know their efforts were a success. After those changes took effect, the units Dr. Pronovost worked with decreased their rate of infection by 70%. Today, all fifty states are implementing Dr. Pronovost's programs, which have the potential to save more lives than any other medical innovation in the past twenty-five years.