Subjects: 84,182 patients admitted to specialty and general ICUs with an admitting diagnosis or procedure of acute coronary syndrome, ischemic stroke, intracranial hemorrhage, pneumonia, abdominal surgery, or coronaryartery bypass graft surgery. ICU type was determined by a local data coordinator at each site. Patients were classified by admission to a general ICU, a diagnosis-appropriate (“ideal”) specialty ICU, or a diagnosis-inappropriate (“nonideal”) specialty ICU.