Cost-minimization analysis of alternative diagnostic approaches in a modeled patient with non-small cell lung cancer and subcarinal lymphadenopathy

Objective: To evaluate the costs of alternative diagnostic evaluations of enlarged subcarinal lymph nodes (SLNs) in modeled patients with non-small cell lung cancer (NSCLC). Methods: A cost-minimization model was used to compare 5 diagnostic approaches in the evaluation of enlarged SLNs in modeled patients with NSCLC. Values for the test performance characteristics and prevalence of malignancy in patients with SLN were obtained from the medical literature. The target population was adult patients known or suspected to have NSCLC with SLNs with a short axis length of at least 10 mm on thoracic computed tomography (CT). Results: The lowest-cost diagnostic work-up was by initial evaluation with endoscopic ultrasonography-guided fine-needle aspiration (EUS FNA) biopsy ($11,490 per patient) compared with mediastinoscopy (with biopsy) ($13,658), transbronchial FNA biopsy ($11,963), CT-guided FNA biopsy ($13,027), and positron emission tomography ($12,887). The results were sensitive to rate of SLN metastases and EUS FNA sensitivity. The EUS FNA biopsy remained least costly if the probability of SLN metastases exceeded 24% or EUS FNA sensitivity was higher than 76%. Primary mediastinoscopy was the most economical if not. Conclusions: Which testing strategy is least costly for SLN evaluation in a modeled patient with NSCLC may be determined by the pretest probability of nodal metastases. Use of EUS FNA biopsy minimizes the cost of diagnostic evaluation in most cases.