Cost Effectiveness Analysis Evaluating Real-Time Characterization of Diminutive Colorectal Polyp Histology using Narrow Band Imaging (NBI)

Abstract

Background: Endoscopists and new computer-aided programs can achieve performance benchmarks for real-time diagnosis of colorectal polyps using Narrow-Band Imaging (NBI), though do not perform as well as endoscopists with expertise in advanced imaging. Previous cost-effectiveness studies on optical diagnosis have focused on expert performance, potentially over-estimating its benefits.

Aim: Determine cost-effectiveness of an NBI ‘characterize, resect and discard (CRD)’ strategy using updated assumptions based on non-expert performance.

Methods: Markov model was constructed to compare cost-effectiveness of the CRD strategy, where diminutive polyps characterized as non-adenomas with high confidence are not resected and adenomas are resected and discarded, versus standard of care (SOC) in which all polyps are resected with histologic analysis. Rates related to NBI performance, missed polyps, polyp progression, malignancy, and complications, as well as quality-adjusted life years (QALYs) were derived from the literature. Costs were age and insurer-specific. Mean QALYs and costs were calculated using first order Monte Carlo simulation. Deterministic and probabilistic sensitivity analyses were conducted.

Results: The mean QALY estimates were similar for the CRD (8.563, 95% CI: 8.557-8.571) and SOC strategy (8.563, 8.557-8.571), but costs were reduced ($2,693.06 vs. $2,800.27, mean incremental cost savings: $107.21/person). Accounting for colonoscopy rates, the CRD strategy would save $708 million to $1.06 billion annually. The model was sensitive to the incidence of tubular adenomas; the results were otherwise robust in all other one-way and probabilistic analyses.

Conclusions: An NBI CRD strategy is cost-effective when compared to the SOC, even when employed by non-experts. The appreciated benefit is primarily due to cost savings of the CRD strategy.