27: Costs of delayed vs intraoperative recognition of lower urinary tract injury at the time of laparoscopic hysterectomy

Abstract

To evaluate the direct medical costs associated with delayed versus immediate recognition of lower urinary tract injury (LUTI) at the time of laparoscopic hysterectomy and estimate the relative costs and savings associated with universal cystoscopy (UC) as compared to selective cystoscopy (SC). A decision tree model was used to estimate the costs associated with delayed vs intraoperative recognition of LUTI at the time of laparoscopic hysterectomy for benign indications. Probability distributions of injury and its associated complications were drawn from published literature. Where multiple published probabilities were available, a sample-size-weighted average was used with a PERT distribution. Healthcare payer costs were drawn from 2016 Centers for Medicare and Medicaid Services national reimbursement schedules and included estimated physician fees, anesthesia fees, facility fees, imaging fees and pathology fees, using Current Procedural Terminology or Diagnosis Related Group codes as appropriate. The payer cost of cystoscopy was estimated using bundled outpatient reimbursement rates, as it is not separately billed at the time of hysterectomy. Total costs were estimated under both SC and UC. SC assumed an average 25% cystoscopy rate based on published literature. A three-way threshold analysis was performed to determine the proportion of LUTI with delayed diagnosis that would need to be diagnosed intraoperatively to favor UC under three scenarios: low injury rates (0.5%; estimated using pooled retrospective and prospective data), high injury rates (4%; estimated using prospective data with universal screening), and moderate injury rates (2.2%). Probabilistic sensitivity analysis was used to assess the robustness of the findings. Given insufficient data, no other healthcare system costs, such as malpractice liability, differential operating room time, or out-of-pocket expenses were included. The SC estimated cost of laparoscopic hysterectomy, inclusive of LUTI complications, ranged from $8,807 to $9,132, while the UC cost ranged from $8,962 to $9,034. Assuming high LUTI rates, UC can be cost saving with ureteral injury detection rates above 50% or bladder injury detection rates above 96%; maximal estimated costs savings were $98 per hysterectomy. UC does not achieve cost savings to the payer assuming low injury rates with a median incremental cost of $143 per hysterectomy (incremental cost to prevent one delayed diagnosis $113,186). Moderate injury rates were estimated to be cost neutral. Estimated UC costs vary based on LUTI rates, and UC policy has the potential to be cost saving through increased intraoperative diagnosis of LUTI. When not cost saving, the incremental costs of UC are modest and may still be outweighed by other health system and malpractice liability costs not accounted for within this model.