Cognitive Complexity of the Medical Record Is a Risk Factor for Major Adverse Events

Patients in tertiary care hospitals are more complex than in the past, but the implications of this are poorly understood as “patient complexity” has been difficult to quantify. A “Complexity Ruler” was validated and tested in a case-control model of all patients with major adverse events at a tertiary care pediatric hospital from 2005 to 2006. Above empirically derived cutoffs, 24-hour and lifetime cognitive complexity of the medical records were risk factors for major adverse events.