An Economic Analysis of Screening for Amblyopia: Influences of Prevalence, Test Cost, Test Quality, Value of Detection, Sensitivity and Specificity

When is it profitable to screen for amblyopia? In order to answer this question, we must place some values on the various outcomes of screening. What is the value of finding an amblyope at an early age? What is the cost of a false positive, a false negative, or a true negative? Because it is not easy to provide answers to these questions, the method of this paper is to investigate a range of assumptions, the possible values in this pay-off matrix. These are coupled with screening tests of various quality in order to find the minimum prevalence of the disease for which it would be profitable to screen. Indeed, the prevalence of amblyopia is itself unknown, variously estimated at between 0.05 and 0.005 (Ciuffreda et al. 1991; Oliver & Nawratzki, 1971) in normal populations.