Identifying High Direct Variable Costs of Open Carpal Tunnel Release Patients Using Time-Driven Activity-Based Costing

Abstract

To improve value in health care delivery, a deeper understanding of the cost drivers in hand surgery is necessary. Time-driven activity-based costing (TDABC) more accurately reflects true resource use compared with traditional accounting methods. This study used TDABC to explore the facility cost of carpal tunnel release and identify preoperative characteristics of high-cost patients. Using TDABC, we calculated the facility costs of 516 consecutive patients undergoing open carpal tunnel release at an orthopedic specialty hospital between 2015 and 2021. Patients in the top decile cost were defined as high-cost patients. Multivariable logistic regression was used to determine preoperative characteristics (age, sex, body mass index, race, ethnicity, Elixhauser comorbidity index, American Society of Anesthesiology score, preoperative Disabilities of the Arm, Shoulder and Hand score, Short-Form 12, and anesthesia type) independently associated with high-cost patients. Surgery-related personnel costs were the main driver (38.0%) of total facility costs, followed by preoperative personnel costs (21.3%). There was a 1.8-fold variation in facility cost between patients in the 90th and 10th percentiles ($774.69 vs $431.35), with the widest cost variations belonging to medication costs ($17.67 vs $1.85; variation, 9.6-fold) and other supply costs ($213.56 vs $65.56; variation, 3.3-fold). Using multivariable regression, predictors of high cost were patient age and use of general anesthesia. Total facility costs correlated strongly with the total operating room time and incision to closure time. Efforts to decrease operating room time may translate into reduced personnel costs and greater cost savings. Multidisciplinary initiatives to control medication expenses for patients at risk of high costs may narrow the existing variation in costs. Economic and Decision Analysis II.