Comparing the cost-effectiveness of three diagnostic test strategies for angle closure in a developing country

Abstract

Background/Aims The appropriate roles for alternative diagnostic tests in detecting primary angle closure of the eye are uncertain. This study evaluated the cost-effectiveness of Scheimpflug camera imaging, the van Herick technique and gonioscopy to identify primary angle in a developing country. Methods This cross-sectional diagnostic study included participants aged >40 years with suspected primary angle closure in the developing country of Brazil. All participants underwent Scheimpflug camera imaging, a van Herick test and gonioscopy. The diagnostic ability of these tests was evaluated using a receiver operating characteristic curve. Costs of interventions were derived using the Brazilian Hierarchical Classification of Medical Procedures. The cost-effectiveness of the tests were compared using an incremental cost-effectiveness ratio. Results Gonioscopy was confirmed to be the most accurate diagnostic test for primary angle closure, closely followed by the van Herick test. The accuracy of Scheimpflug camera imaging was considerably lower, largely because of its low sensitivity. The incremental cost-effectiveness ratio demonstrated that Scheimpflug camera imaging was also the least cost-effective, as it was considerably more expensive but with less clinical benefits. Conclusions Because of its relatively low accuracy and high costs, Scheimpflug camera imaging is not as cost-effective as gonioscopy nor the van Herick test as a means of diagnosing primary angle closure in a developing country.