Trends in comorbidities and complications among patients undergoing inpatient spine surgery

Study Design. Retrospective database study. Objective. We sought to identify trends in demographics, comorbidities, and postoperative complications among patients undergoing ACDF and PLF. Summary of Background Data. As demand for anterior cervical discectomy and fusion (ACDF) and posterior lumbar fusion (PLF) surgery continues to increase, it is important to understand changes in the healthcare system and patient populations undergoing these procedures. Methods. We identified 220,520 ACDF and 151,547 PLF surgeries (2006–2016; Premier Healthcare database). Annual proportions or medians were calculated for patient and hospital characteristics, and (Elixhauser) comorbidities. Postoperative complications, including blood transfusions, cardiovascular, pulmonary, renal, or wound complications, hemorrhage, stroke, sepsis, thromboembolism, delirium, inpatient falls, and mortality, were reported per 1000 inpatient days. Trends were assessed by Cochran–Armitage tests and linear regression for binary and continuous variables, respectively. Results. The median age of patients undergoing ACDF and PLF increased significantly from 2006 to 2016 (50 to 57 yr and 58 to 61 yr, respectively; P<0.001) coinciding with an increasing comorbidity burden (30.2% to 47.9% and 44.9% to 55.7%, respectively representing the share of patients with 2 Elixhauser comorbidities; P<0.001). Overall rate of any complication experienced a significant decline after both ACDF (24.5 to 20.8 per 1000 inpatient days; P ¼0.002) and PLF (30.5 to 23.1 per 1000 inpatient days; P<0.001). Conclusion. The comorbidity burden of patients undergoing ACDF and PLF increased substantially from 2006 to 2016, however without a corresponding increase in overall complication rate. Understanding these changes can help guide future practice, advise in the allocation of resources, and inform future areas of research.