Number Needed to Treat as a Tool for Cost Effectiveness Analysis: A Case Study in Renal Transplantation

Abstract

Objective: To assess the utility of number needed to treat (NNT) as a tool for cost effectiveness analysis.
 Methods: Two monoclonal antibodies (MAbs), used for induction therapy viz basiliximab and daclizumab in renal transplantation, were identified. Pivotal placebo controlled clinical trials, mentioned in the innovator package inserts, were compared and analyzed for acute graft rejection and graft survival at 12 mo. NNT viz-a-vis cost was calculated and compared.
 Results: Daclizumab was comparable to basiliximab for acute graft rejection (NNT 10 vs. 9) but better for graft survival (20 vs. 25) at 12 mo, when used along with triple drug regimen (cyclosporine, azathioprine and corticosteroid). However, considering the cost of regimen for these drugs, in terms of NNT, basiliximab was more cost effective (INR 12,52,044 vs. 28,70,400 for acute rejection and INR 34,77,900 vs. 57,40,800 for graft survival). On the other hand, when these MAbs were used along with dual drug regimen (cyclosporine and corticosteroid), daclizumab was more cost effective for graft survival at 12 mo. The higher cost of daclizumab regimen (INR 2,87,040 vs. 1,39,116 for basiliximab) was offset by its substantially lower NNT (20 vs. 58-75 for one extra graft survival at 12 mo).
 Conclusion: This study demonstrates the utility of NNT in ascertaining relative effectiveness of treatment modalities that would help to formulate appropriate healthcare policies.