Severity Weighting of Postoperative Adverse Events in Orthopedic Surgery

Studies of adverse events (AEs) after orthopedic surgery commonly use composite AE outcomes. An example of such an outcome is any AE. These types of outcomes treat AEs with different clinical significance (eg, death, urinary tract infection) similarly. We conducted a study to address this shortcoming in research methodology by creating a single severity-weighted outcome that can be used to characterize the overall severity of a given patient's postoperative course. All orthopedic faculty members at 2 academic institutions were invited to complete a severity-weighting exercise in which AEs were assigned a percentage severity of death. Mean (standard error) severity weight for urinary tract infection was 0.23% (0.08%); blood transfusion, 0.28% (0.09%); pneumonia, 0.55% (0.15%); hospital readmission, 0.59% (0.23%); wound dehiscence, 0.64% (0.17%); deep vein thrombosis, 0.64% (0.19%); superficial surgical-site infection, 0.68% (0.23%); return to operating room, 0.91% (0.29%); progressive renal insufficiency, 0.93% (0.27%); graft/prosthesis/flap failure, 1.20% (0.34%); unplanned intubation, 1.38% (0.53%); deep surgical-site infection, 1.45% (0.38%); failure to wean from ventilator, 1.45% (0.48%); organ/space surgical-site infection, 1.76% (0.46%); sepsis without shock, 1.77% (0.42%); peripheral nerve injury, 1.83% (0.47%); pulmonary embolism, 2.99% (0.76%); acute renal failure, 3.95% (0.85%); myocardial infarction, 4.16% (0.98%); septic shock, 7.17% (1.36%); stroke, 8.73% (1.74%); cardiac arrest requiring cardiopulmonary resuscitation, 9.97% (2.46%); and coma, 15.14% (3.04%). Future studies may benefit from using this new severity-weighted outcome score.