Elective lumbar fusion in the United States: national trends in inpatient complications and cost from 2002-2014

BACKGROUND: Elective fusions for degenerative spine disease have increased over the past two decades in the USA, with variability in complications and hospital costs. The additional service costs associated with adverse perioperative events remain unknown. Our objective is to improve understanding of trends in safety and cost of elective lumbar fusions on a national scale. METHODS: A weighted sample of 1, 526, 386 adults undergoing elective lumbar fusion for degenerative indications were identified in the National Inpatient Sample (NIS) years 2002-2014. Twelve categories of major complications by system, and patient/hospital variables, were evaluated as predictors of the overall reimbursed cost. Mean differences (B) and 95% confidence intervals 95% CI are reported. Significance is assessed at P<0. 001. RESULTS: Nineteen percent of patients experienced inpatient complication. After adjusting for inflation, the mean overall cost was 32, 802±19, 557. Costs increased with presence of each of the 12 categories of complications, and by number of levels fused. Rates of most frequent complications and their adjusted cost-of-care were acute postoperative anemia (11. 2%, B= 1817 1722-1913, P<0. 001), renal/urinary (1. 9%, B= 510 288-732, P<0. 001), pulmonary (1. 8%, B= 6014 5785-6243, P<0. 001) and gastrointestinal (1. 8%, B= 3699 3490-3908, P<0. 001). The costliest adverse events were infection (B= 15, 882 [ 15, 424-16, 339, P<0. 001), thromboembolism (B= 8856 8400-9311, P<0. 001), hematoma/seroma/vascular (B= 8050 7784-8316, P<0. 001). CONCLUSIONS: The number of elective lumbar fusions for degenerative spine disease increased 276% in the USA from 2002-2014 with growing surgeon preference for lateral techniques, and an increasing proportion of combined anterior and posterior approaches. Overall complication rates decreased from 2002-2014, despite an older patient population. After adjusting for inflation, cost was relatively stable across years 2002-2014. Complications by system were associated with increased cost, underscoring the need to address sources of complications and optimize early postoperative recovery in order to reduce healthcare expenditure.