Time-Driven Activity-Based Costing in Interventional Oncology: Cost Measurement and Cost Variability for Hepatocellular Carcinoma Therapies

Purpose: To use time-drive activity-based costing (TDABC) to characterize and compare costs of transarterial chemoembolization (TACE), transarterial radioembolization (TARE), and ablation.

Methods: This three-part study involved (1) prospective observation to record resources used during TACE, TARE, and ablation and statistical evaluation of interobserver and interprocedure variability; (2) Bland-Altman analysis of prospective measurements and medical record time stamps to establish practicality of using retrospective data in place of direct observation; (3) retrospective time stamp assessment for 117 ablations, 61 TACE procedures, and 61 TARE procedures to reveal variability drivers.

Results: Ablation costs were lowest ($3,744), which were 74% of TACE costs ($5,089) and 18% of TARE costs ($20,818). Consumables were the greatest cost contributor, accounting for 65% of ablation, 58% of TACE, and 90% of TARE costs. A single consumable contributed to most of the overall costs: the ablation probe (42%), ethiodized oil for TACE (30%), and yttrium-90 microspheres for TARE (80%). Bland-Altman analysis showed agreement between retrospective time stamps and prospective measurements. Ablation costs increased from $3,288 to $4,245 to $4,461 for one, two, or three tumors treated. TACE cost increased from $5,051 to $5,296 for lobar versus selective approaches.

Conclusion: A bottom-up costing approach using TDABC is feasible to assess true costs of hepatocellular carcinoma treatments and demonstrates ablation costs are significantly less than those of TACE and TARE. Replication of these methods at other institutions can facilitate development of a bundled payment model to promote utilization of locoregional therapies for hepatocellular carcinoma.