Study design: Retrospective cohort study.
Objective: To determine the trends and causes for increases in hospital charges in adolescent idiopathic scoliosis (AIS) fusions.
Summary of background data: Trends in utilization rates, surgical procedure types, and hospital charges for AIS fusions have not been well investigated.
Methods: We used International Classification of Diseases, Ninth Revision, billing codes to identify 29,594 AIS fusion cases from the National Inpatient Service (NIS) database between 2001 and 2011. Data were trended over time, and contrasted against other common procedures. To identify specific drivers of charges, we queried our own hospital's billing system, and averaged charges from 40 cases (10 cases for each of 4 yr studied). Dollar amounts were adjusted for inflation to 2011 dollars.
Results: Utilization rates for AIS fusions have remained constant, whereas utilization of adult spinal fusions increased by 64% (P = 0.0004). Utilization of anterior thoracic fusions decreased by 80% (P < 0.0001). Mean hospital charges for AIS spinal fusions increased from $72,780 in 2001 to $155,278 in 2011 (113% increase), averaging 11.3% annually (P < 0.0001), with charges for adult spinal procedures increasing at a similar rate (13.4% annually, P < 0.0001). Charges for the other nonspine conditions increased to a lesser degree (range of 4.5%-6% annually, P < 0.001 for each). At our institution, spinal implant charges increased 27.6% annually, whereas surgeon charges decreased 0.5% annually, and all other charges increased only 5.2% annually. Over time, our surgeon used greater numbers of pedicle screws, and greater numbers of implants per surgery and per level fused (P < 0.05 for each). Implant charges were 28% of the total hospital bill in 2003, rising to 53% in 2012.
Conclusion: Although utilization rates for AIS fusions have remained constant over time, hospital charges have increased substantively, and there has been a shift toward performing posterior only surgical procedures. This corresponds to the widespread adoption of pedicle screw-based constructs. Spinal implants may be the primary driver of increased charges. Strategies directed toward implant cost savings may thus have the largest impact.
Level of evidence: 4.