111. Drivers of cost in primary single-level lumbar fusion surgery

BACKGROUND CONTEXT Allocating costs associated with resources utilized during health care delivery is challenging with traditional hospital accounting. Time-driven activity-based costing (TDABC) is an efficient method to accurately assign cost that has been well described in the management and health economics literature. TDABC allows for the determination of difficult to quantify costs, leading to a more informative cost structure. PURPOSE To characterize the variation in direct total hospital cost (THC) between lumbar fusion approaches and between surgeons performing these procedures. STUDY DESIGN/SETTING Retrospective review of records (2015-2017). PATIENT SAMPLE The study included 727 patients who underwent primary single-level lumbar fusion surgery for degenerative disease at a single institution by 12 different surgeons. Patients were treated with either anterior lumbar interbody fusion (ALIF), lateral lumbar interbody fusion (LLIF), transforaminal lumbar interbody fusion (TLIF), instrumented posterolateral fusion (PLF) or in-situ fusion (ISF). OUTCOME MEASURES Differential cost between surgical approaches and surgeons. METHODS Process maps were developed for preoperative, intraoperative and postoperative care at the institution studied. THC was composed of implant, medications, other supplies (eg, dressings), and personnel costs and calculated using Avant-garde Health (Boston, MA). Linear regression and descriptive statistics were used to analyze THC variation. RESULTS Approximately 50% of THC variation was associated with procedure choice alone. Patient characteristics explained 10% of THC variation. Implants (including biologics) accounted for 45% of cost, surgery personnel 27%, inpatient personnel 16%, medication and non-implant supply 8%. With reference to PLF, THC ranged from 0.6x (ISF) to 1.7x (LLIF). Implant cost variation ranged from 2.5x reference (LLIF) to 0.1x (ISF). There was a 1.7x difference between the highest THC surgeon and the lowest. The fusion type with the highest THC variation was TLIF. The surgeon with the highest TLIF THC was 1.5x more expensive than the surgeon with the lowest. CONCLUSIONS Surgeon-based choices (fusion technique, implants) have the greatest effect on THC variation and represent the largest opportunities for cost savings. Primary single-level lumbar fusion THC is driven primarily by fusion type. Implants, including biologics, account for nearly half this cost. Future work will incorporate outcomes data to characterize the differential value conferred by fusion types with higher THC. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.