How often are adverse events reported in English hospital statistics?

About 850 000 medical errors occur in NHS hospitals every year, resulting in 40 000 deaths.w1In the United Kingdom, the National Patient Safety Agency (NPSA) was created to learn from patient safety incidents occurring in the NHS.w2 In February 2004, it launched a new patient reporting system, drawing together reports of patient safety errors and systems failures provided by health professionals across England and Wales.w3 An adverse event can be defined as “an unintended injury caused by medical management rather than a disease process, resulting in death, life threatening illness, disability at the time of discharge, admission to hospital, or prolongation of hospital stay.” w4 A medical or surgical misadventure is an adverse event that might have been avoided if the patient had received ordinary standards of care. We look at four years of …