Inpatient Postoperative Mortality: Comparing Patients Hospitalized Preoperatively to Those Having Elective Surgery

Abstract

Background: Perioperative death globally has been described as the third leading cause of death behind heart disease and malignant neoplasm and ahead of cerebrovascular disease. However, studies of all-cause perioperative mortality have not distinguished patients who were outpatients preoperatively ("elective") from patients having urgent surgery or having surgery on a day after their date of admission ("nonelective"). Strategies for reducing overall perioperative mortality are affected by whether most deaths occur after elective or nonelective surgery. Methods: The authors studied all adult patients undergoing major diagnostic or therapeutic surgery in Florida in 2021 and 2022 hospitalized 2 or more midnights. They compared those who survived to discharge or died between the elective and nonelective groups. Major hospital-acquired complications were considered as sensitivity analyses. The diversity of procedures (International Classification of Diseases, Tenth Revision-Procedure Coding System [ICD-10-PCS] codes) was quantified using the inverse of the internal Herfindahl. Results: Among the 1,245,537 hospitalizations studied, the nonelective group accounted for 94.5% (95% CI, 94.0 to 95.1%) of the 20,874 in-hospital deaths (P < 0.0001 vs. 50% ["most"]). The nonelective group also accounted for most (70.0%) hospitalizations studied. The relative risk of death in the elective versus nonelective group was 0.13 (95% CI, 0.12 to 0.14; P < 0.0001 vs. 1.0). The relative risks of acute kidney injury, hospital-acquired pneumonia, a major adverse cardiovascular event, and infection were all less than 1.0 in the elective group. Hundreds of different ICD-10-PCS codes occurred commonly among patients who died, in both groups. Conclusions: Results of previous studies of all-cause perioperative mortality should not be applied to patients having elective major surgery because most deaths (approximately 95%) and most cases (70%) are in patients having nonelective major surgery (i.e., already admitted to the hospital or undergoing trauma-related surgery). From a public health perspective, interventions to reduce postoperative mortality should be primarily focused on patients who are inpatients before their first major surgical procedure.