1.4
The Economics of Myopia
Marcus C.C. Lim* and Kevin D. Frick†
The economics of myopia is not well elucidated. Economic evaluation can take several forms. This chapter gives an overview of myopia economics and provides a walkthrough for the calculation of the burden of disease related to worldwide myopia. Directions for further research are suggested.
Introduction
Economic science is the study of allocation of scarce resources. Fundamentally, all forms of economic evaluation are undertaken for one reason: Resources are limited and decision makers need guidance (which is all that economic evaluation can provide) for making resource allocation decisions between alternatives. In health economics, resources include time (for the patient and any caregivers), money, medical manpower and other resources to produce health and health services. Economists are interested in the modification of resource allocation or prices that will change the way those resources are allocated and bring about a change in health. With regard to myopia, questions that can be answered at a local or global level by an economic evaluation include:
•What is the cost of vision correction for myopia?
•What is the total cost related to myopia, combining vision correction, the costs of treating associated eye disease as well as loss of productivity?
*Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751.
†Johns Hopkins Bloomberg School of Public Health, 624 N. Broadway, Rm. 606, Baltimore MD 21205, USA. E-mail: kfrick@Jhsph.edu
63
64M.C.C. Lim and K.D. Frick
•What benefits are there from vision correction of myopia? What is the magnitude of future costs that will be offset?
•Does government subsidization of spectacles for myopes make economic sense?
•How much could we save if there was a cure for myopia?
Economic evaluations
One purpose of economic evaluation is to describe and compare the costs and benefits of health care services. This type of analysis can help us to answer any of the questions above. One methodological step necessary to perform economic analysis is to decide what set of costs and benefits should be measured. The set of costs and benefits considered is defined by the perspective taken, using economic jargon. The perspective could be the hospital, the Ministry of Health, the government as a whole or society. Generally, economists favor analyses at the broadest category, society. From a societal perspective, an economic evaluation of myopia would describe and compare the inputs (costs) and outputs (benefits) of treating myopia for all those who are affected. The costs include the cost of optical correction of myopia, in the form of spectacles, contacts lenses and refractive surgery, regardless of who pays. The benefits include increased productivity and increased quality of life.
Since the outcome of every economic evaluation depends on both the action contemplated and the alternative, it is important to specify the alternative. The alternative could be the status quo. If it is, the status quo must be precisely defined. In our example, a course of action might be for government to fund spectacles for myopes. This would be compared with the status quo alternative, which could be to continue with private funding.
Full vs partial evaluations
Economic evaluations can be classified into full or partial evaluations by the answers to the following two questions1:
1)Does the evaluation look at both costs and benefits?
2)Does it involve two or more alternatives?
Translating these answers into a form of economic evaluation is demonstrated in the table below.1
65 The Economics of Myopia
|
YES |
CEA, CUA |
Partial |
|
Does the |
or CBA |
|||
|
|
|||
|
|
|
||
evaluation |
|
|
|
|
look at |
|
|
|
|
both costs |
|
|
|
|
and |
|
|
A description |
|
benefits? |
NO |
Partial |
||
of costs or |
||||
|
|
|
benefits |
|
|
|
|
|
|
|
|
YES |
NO |
Does it involve two or more alternatives?
The differences between cost-effectiveness analysis (CEA), cost-utility analysis (CUA) or cost-benefit analysis (CBA) are the means of valuing the health benefit. For CEA, the benefit measure is usually stated as $/change in disease-specific measure of health-related benefits. For CUA, the result is stated as $/Quality-Adjusted Life Year (QALY); for CBA, it is stated as “Net benefit” ($(benefit)–$(cost)). In international settings, the result can be expressed in local currency units.
Economic evaluation of myopia
Why perform an economic evaluation of myopia? Cynics might suggest that this is an academic exercise and nothing more, as the correction of myopia is not funded by the state in most countries. Free markets do not require economic evaluations as it is assumed that individuals will only make decisions that benefit their own interests. Countries that make provincial or national provision and coverage decisions are more likely to use economic evaluations, e.g. the United Kingdom, Canada and Australia and not the United States. For example, in the United States, multiple private insurers fund a significant portion of healthcare (for which the market measures value rather than simulating a market through an economic evaluation) while in the United Kingdom, it is the governmentcontrolled National Health Service, the world’s third largest employer, who funds healthcare. Nevertheless, screening programs for refractive error are becoming increasingly common throughout the world.2 In addition, research has shown that off-the-shelf spectacles are suitable for a large