Cost-effectiveness of CT scanning compared with mediastinoscopy in the preoperative staging of lung cancer.

In lung cancer, evaluation of the mediastinum is a critical factor in the determination of surgical resectability. Mediastinoscopy with nodal biopsy has been the preferred method of assessing the mediastinum. An alternate approach is to first perform computed tomography (CT) and then decide on the need for further tests. The present study is a cost-effectiveness analysis of these two diagnostic strategies. A decision tree was constructed incorporating the two approaches. Costs were determined in a rigorous manner by calculating a fully allocated unit price for all relevant hospital services. These costs include both direct costs and an appropriate share of support and overhead expenses. The frequency of complications with the tests, the need for further tests, and the expected outcomes for the patients were derived from published data. Hospital charts were reviewed to determine the amount of services used by patients who had actually experienced the outcomes or complications of interest. The comparative costs of the two strategies were then determined by multiplying the fully allocated unit costs by the amount of services that a cohort of patients could be expected to use following one or the other pathway. The strategy employing CT scanning and selective mediastinoscopy resulted in a reduction of costs and in hospital days ranging from 10% to 30%. CT scanning and selective mediastinoscopy are, therefore, more cost-effective than mediastinoscopy alone in the preoperative staging of lung cancer.