Objectives: All gastric ulcers discovered at endoscopy are potentially malignant. Concurrent use of both histological biopsy and cytological brushing has been advocated as a means of increasing the diagnostic yield for neoplasia at the time of initial endoscopy. The purpose of this analysis was to determine the impact of these diagnostic strategies on the cost-effectiveness of detecting malignancy in patients with a gastric ulcer.
Methods: The diagnostic performance of biopsy and brushings in detecting gastric malignancy was estimated from a meta-analysis of published reports. Nondiscounted direct costs were determined from patient resource consumer profiles from the perspective of a Canadian hospital. A decision tree was used to compare diagnostic strategies (biopsy alone, brushing alone, or biopsy and brushing) in a hypothetical cohort of patients found to have a gastric ulcer at endoscopy. Effectiveness was expressed as diagnostic days saved.
Results: No strategy achieved dominance. The brushing strategy was the most cost-effective, but its cost-effectiveness ratio was only slightly lower than that of biopsy. Cost differences between the biopsy and brushing strategies were small (less than $6 per case). Performing both biopsy and brushing slightly improved the true-positive rate but resulted in a doubling of the false-positive rate, which in turn led to unnecessary laparotomies. The impact of the high false-positive rate was also seen in the incremental cost of performing both brushings and biopsy ($168-$423 per case).
Conclusions: For gastric ulcers discovered at endoscopy, the preferred strategy is to perform either cytological brushing or histological biopsy. The previously recommended strategy of performing both cytological brushing and histological biopsy should be reconsidered.