A patient-reported spectrum of adverse health care experiences: harms, unnecessary care, medication illness, and low health confidence.

As part of a health "checkup," a large national sample of adults used an Internet technology that also asks about adverse experiences. About half of all respondents do not feel very confident they can manage and control most of their health problems, almost 30% consider that their hospital or emergency department use was unnecessary, 20% believe that their medications may be causing illness, and 1.5% report a medical-related harm. Routine measures across a spectrum of adverse experiences are easy to obtain as part of everyday practice. Attention to these measures by health professionals should make care safer and less wasteful.