Preoperative paravertebral blocks for the management of acute pain following mastectomy: a cost-effectiveness analysis

Purpose: Preoperative paravertebral blocks (PPVBs) are routinely used for treating post-mastectomy pain, yet uncertainties remain about the cost-effectiveness of this modality. We aim to evaluate the cost-effectiveness of PPVBs at common willingness-to-pay (WTP) thresholds. Methods: A decision analytic model compared two strategies: general anesthesia (GA) alone versus GA with multilevel PPVB. For the GA plus PPVB limb, patients were subjected to successful block placement versus varying severity of complications based on literature-derived probabilities. The need for rescue pain medication was the terminal node for all postoperative scenarios. Patient-reported pain scores sourced from published meta-analyses measured treatment effectiveness. Costing was derived from wholesale acquisition costs, the Medicare fee schedule, and publicly available hospital charge masters. Charges were converted to costs and adjusted for 2016 US dollars. A commercial payer perspective was adopted. Incremental cost-effectiveness ratios (ICERs) were evaluated against WTP thresholds of 500 and 50,000 for postoperative pain control. Results: The ICER for preoperative paravertebral blocks was 154.49 per point reduction in pain score. 15% variation in inpatient costs resulted in ICER values ranging from 124.40–180.66 per pain point score reduction. Altering the probability of block success by 5% generated ICER values of 144.71–163.81 per pain score reduction. Probabilistic sensitivity analysis yielded cost-effective trials 69.43% of the time at 500 WTP thresholds. Conclusion: Over a broad range of probabilities, PPVB in mastectomy reduces postoperative pain at an acceptable incremental cost compared to GA. Commercial payers should be persuaded to reimburse this technique based on convincing evidence of cost-effectiveness.