Costs of Interventions for Visual Impairment
Article Outline
Purpose
To quantify the economic costs of vision loss in Australia and assess the impact of a costed intervention package to prevent avoidable vision loss.
Design
Existing Australian population-based data on prevalence and causes of visual impairment were used, and costs were calculated from published data for the five main causes of visual impairment.
Methods
The cost of vision loss in Australia was determined from the weighted prevalence of visual impairment; unpublished data on the indirect costs of vision; and national databases on health care costs and other economic data. A costed intervention package was developed and its economic impact modeled. Outcome measures were total costs and savings from the interventions.
Results
The intervention package would cost AU$188.8 million to implement in its first year but would bring a net return of AU$163.1 million in direct costs in the first year and an overall savings to the country of AU$911.1 million, a 4.8-fold return on investment.
Conclusions
Three-quarters of vision loss is avoidable, and many eye care interventions are cost effective. Even a developed economy cannot afford avoidable vision loss. Priority needs to be given to the prevention and treatment of avoidable vision loss.
Although often overlooked, vision loss must be one of the archetypical chronic diseases of adults. Like many other chronic diseases, vision loss is not yet firmly on the international health agenda or recognized as a global health priority. Estimates for 2002 gave a global figure of 36.8 million people who were blind and another 124 million people with marked visual impairment.1 More than 80% of the global total of vision loss occurs in developing countries, and approximately three quarters of this vision loss is avoidable or preventable.2 Globally, there are 17.6 million people bilaterally blind from cataract—a total of 48% of those who are blind. Cataract blindness can be effectively and rapidly reversed with modern intraocular lens cataract surgery. Corneal blindness, whether from trachoma or other causes of corneal scarring, affects approximately 4.2 million people (8.9% of blindness) and is highly amenable to prevention or treatment. Many of the causes of childhood blindness (1.4 million, or 3.9% of global blindness) are amenable to treatment. Most of the blindness due to diabetic retinopathy (1.8 million, or 4.8% of blindness) is preventable with appropriately timed treatment, as is the blindness from glaucoma (4.5 million, or 12.3% of total).
In developing countries, many of the issues around the prevention of blindness involve the provision of effective, accessible, and affordable services through the provision of primary and secondary eye care. These services require the development of effective and sustainable disease control strategies; appropriate development of human resources with the creation of eye care teams; and the provision of appropriate and affordable infrastructure and technology. These are the three strategies of the Global Initiative’s VISION 2020: The Right to Sight, which aims to eliminate avoidable blindness by 2020.3, 4
However, developed countries also share in the epidemic of increasing eye disease and vision loss that is driven by population aging and social and environmental changes. Population-based studies from Australia, Europe, and the United States have demonstrated that the prevalence of blindness and vision loss approximately triples with each decade of life over the age of 40.5, 6 After controlling for age, men and women are equally affected by vision loss.
Previously we reported that the overall economic impact and cost of vision loss in Australia and showed that the total cost of vision loss in 2004 was $9.85 billion.7 The current study builds on those data, and as foreshadowed by Frick and Kymes,8 once the overall costs have been established, it is possible to undertake an economic evaluation to compare a change in the national economic impact over time with the costs of the program necessary to achieve that change.
In this report, we present a costed intervention package that we propose to address the avoidable and preventable blindness in a developed country. The overall rate of return for each dollar spent in the prevention and treatment of eye disease is 4.8.
Methods
Population-Based Data on Eye Disease
The prevalence of vision impairment in Australia has been previously reported.9 In 2004, a total of 480,000 Australians were estimated to have vision impairment (presenting visual acuity <6/12), including 50,000 who were blind (presenting visual acuity <6/60). Five conditions—age-related macular degeneration, cataract, diabetic retinopathy, glaucoma, and undercorrected refractive error—caused 90% of vision impairment and 78% of blindness. Among those older than 40, refractive error accounts for only 4% of blindness, but for 62% of low vision.
As previously reported, we took these data and other data on age-specific prevalence rates by gender, mortality rates, morbidity, service use, and socioeconomic impact derived from combined data sets.7, 10
Health Economic Data
Data were obtained from the Australian Institute of Health and Welfare and the National Centre for Health Program Evaluation.11 As previously reported, these data were used to calculate direct health costs for eye care in 2004.7, 10
Two groups of indirect costs were calculated. One was the indirect financial costs, which include loss of earnings due to disability or premature mortality, the costs to caregivers, and the costs associated with low vision aids and other appliances. The other nonfinancial indirect costs result from the loss of well-being (burden of disease) and were calculated from the years of healthy life lost. The disability weight for vision loss used was 0.43.12 The value of a statistical year of life in Australia in 2004 was estimated to be AU$162,561.10 A full description of the model and the inputs used is available on our Web site.13
Intervention Platform
A comprehensive consultation process with those involved in eye care and health service provision led to the development of a costed platform of strategic policy interventions that would eliminate preventable blindness and vision impairment through early detection, prevention, rehabilitation, education, and research (Table 1). These interventions were modeled individually. The models examined the delivery mechanism required for each intervention, patient compliance with treatment or recommendations, the estimated impact and effectiveness in reaching the target population, and an assessment of the immediate and secondary costs and benefits.
TABLE 1. Proposed Eye Care Interventions
| Group 1 |
 Health Promotion Awareness, Detection and Prevention |
| 1.1 Promote and fund regular eye examinations |
| 1.1.1 Five-year exams for low-risk 40- to 74-year-olds |
| 1.1.2 Two year exams for higher-risk groups: |
| - Elderly, 75+ years |
| - Aboriginal and Torres Strait Islander people |
| - Diabetes |
| - Family history of glaucoma |
| 1.2 Promoting the cessation of smoking to reduce AMD and cataract |
| 1.3 Health promotion campaigns for the use of ultraviolet-absorbent sunglasses to reduce cataract |
| 1.4 Promote use of low-vision rehabilitation |
| 1.5 Occupational and home health safety campaigns to prevent eye injuries |
| 1.6 Increase community awareness of the importance of appropriate vision care |
| Group 2 |
| Enhanced Models of Treatment and Care |
| 2.1 Reduce cataract surgery waiting lists by outsourcing to the private sector or increasing public sector resources |
| 2.2 Improve access to existing government-subsidized spectacle programs |
| 2.3 Provide sustainable funding for retinal photography for screening for diabetic retinopathy |
| 2.4 Provide sustainable funding for cost-effective therapies for AMD |
| 2.5 Improve access to visiting eye health services for Australian and Torres Strait Islanders |
| Group 3 |
| Eye Research and Development |
| 3.1 Develop a process to increase funding for eye research to national average |
| 3.2 Develop a process to prioritize eye research |
| Group 4 |
| Professional Education and Workforce Development |
| 4.1 Proposed interventions require 113 ophthalmologists and 137 FTE optometrists; workforce needs to be addressed through increasing training and sharing workloads between eye care professionals and other health workers |
Future Projections
The health cost projections to 2024 were calculated by age group by using demographic data from the Australian Bureau of Statistics.14 Health cost inflation rates were calculated by conservative estimates, including the historical average annual inflation rate of 2.8%.10
Results
We have shown that the total cost of vision disorders in Australia in 2004 was estimated to be AU$9.85 billion.7 The total cost of the eye care intervention package we have developed for 2005 and 2006 was AU$188.8 million (Table 2).
TABLE 2. Eye Care Interventions, Costs, Benefits, and Cost-Effectiveness Analysis
| Intervention Group⁎ | Variable | 2005 to 2006 | Lifetime | ||||
|---|---|---|---|---|---|---|---|
| Total Costs (AU$m) | Net Benefit (AU$m) | AU$m/QALY | Total Costs (AU$m) | Net Benefit (AU$m) | AU$m/QALY | ||
| Group 1: Awareness, Detection, and Prevention (total costs 2005 to 2006: AU$90.0m) | |||||||
| 1.1 | Eye examinations | ||||||
| 1.1.1 | Five-year examinations for 40- to 74-year-olds | 2.1 | 0.7 | CS | 41.3 | 4.4 | CS |
| 1.1.2 | Elderly (75+ years) | 59.9 | −7.3 | 5,068 | 473.4 | −102.7 | 9,641 |
| Aboriginal | 2.0 | 1.1 | CS | 28.7 | 9.5 | CS | |
| Diabetes | 8.9 | −0.2 | 1,715 | 212.7 | −57.8 | 27,274 | |
| Glaucoma | 0.5 | 0.2 | CS | 10.4 | 1.3 | CS | |
| 1.2 | Smoking | 3.7 | −3.6 | 2,860,384 | 3.7 | 39.1 | CS |
| 1.3 | Ultraviolet protection | 0.9 | −0.9 | Infinite | 0.9 | 96.6 | CS |
| 1.4 | Low vision | 9.1 | 14.4 | CS | 61.8 | 120.9 | CS |
| 1.5 | Eye trauma | 0.9 | −0.76 | 5,172,295 | 0.9 | −0.1 | 46,342 |
| 1.6 | General awareness | 2.0 | −1.9 | 16,667 | 6.1 | −1.8 | 1297 |
| Group 2: Models of Treatment and Care (total costs 2005 to 2006: AU$79.0m) | |||||||
| 2.1 | Cataract surgery | 63.0 | −23.4 | 16,280 | 63.0 | −23.4 | 16,280 |
| 2.2 | Subsidized spectacle | 3.7 | 28.1 | CS | 71.3 | 500.8 | CS |
| 2.3 | Retinal photography | −3.1 | 3.1 | CS | −75.3 | 75.3 | CS |
| 2.4 | AMD | NA | NA | NA | NA | NA | NA |
| 2.5 | Aboriginal | 15.4 | −15.4 | Undefined | 257.6 | −257.6 | Undefined |
| Group 3: Research and Development (total costs 2005 to 2006: AU$19.7m) | |||||||
| 3.1 | Research funding priority | 19.7NA | −19.7 NA | InfiniteNA | 463.9NA | 257.4NA | CSNA |
| Group 4: Professional Education and Workforce (no additional costs) | |||||||
| 4.1 | Workforce | NA | NA | NA | NA | NA | NA |
The overall package would be highly effective in its first year, costing AU$5591 per quality-adjusted life-year, but would be cost saving thereafter (Table 3). When we include dollars saved from indirect costs in the first year, the initial expenditure of AU$188.8 million would give a total return of AU$911.1 million, or 4.8 times, and over the lifetime of the interventions, a total return of 6.2 would be realized.
TABLE 3. Eye Care Intervention Package, Costs, Benefits, and Cost-Effectiveness for First Three Years if Implemented
| Year | Total Costs (AU$m) | Net Benefit (AU$m) | DALYs Saved | DALYs Expressed as AU$m | Cost-Effectiveness (AU$/QALY) |
|---|---|---|---|---|---|
| 2005to2006 | 188.8 | −25.7 | 4,600 | 748 | 5,591 |
| 2006to2007 | 116.9 | 2.3 | 3,069 | 499 | Cost saving |
| 2007to2008 | 113.6 | 1.2 | 2,969 | 483 | Cost saving |
| Lifetime | 1,620.3 | 661.8 | 47,576 | 7,734 | Cost saving |
Discussion
Blindness and vision loss have a huge and broad-ranging impact in our society. Although much vision loss occurs in developing countries, Australia and other developed economies also need to take vision loss seriously. Australia has good primary, secondary, and tertiary eye care services, as well as good data on the distribution and impact of eye disease. Australia also has comprehensive health economic data that permits economic modeling.
Epidemiologic data show the tripling of vision loss with each decade of life and the impact that vision loss has on independent living and the quality of life.15 These effects will become increasingly important with demographic aging; the number of those with vision loss is likely to double over the next 20 years.3, 4, 15 The current analysis shows that much can be done to prevent vision loss that is not only cost-effective, but indeed cost-saving. This means even developed economies cannot afford not to prevent or treat vision loss.
Eye care has a proven range of low-risk, high-success, and highly cost-effective interventions as measured by cost utility and cost-effective analyses.16 Although cataract surgery is one of the most cost-effective interventions in developing countries, costing as little as US$15 to US$23 per disability-adjusted life-year saved,17 even in developed countries, cataract surgery is still highly cost-effective, at US$2020 per quality-adjusted life-year.18 The key to the proposed interventions is the elimination of avoidable vision loss by prevention or treatment. General and specific eye health promotion messages are included, but much of the work comes down to appropriately timed eye examinations. For asymptomatic low-risk people, these examinations are scheduled every five years for those aged 40 to 74 years, and every two years thereafter. More frequent examination is required for those who notice a change in vision or who are otherwise at higher risk, such as having diabetes or a family history of glaucoma. There is a specific item for the provision of government-subsidized spectacles for eligible people, but otherwise the cost of refraction cannot be separated from the cost of the appropriate eye examinations.
Major advances in the reduction of vision loss can be gained from synergistic collaboration with a range of existing public health programs. Campaigns aimed at tobacco control can have an impact on the reduction of the amount of vision loss due to age-related macular degeneration and cataract.19, 20 Synergy with programs aimed at improving diet and physical activity will not only reduce diabetes, but also reduce the risk of vision loss from diabetic eye disease. Broad partnerships are needed to reduce unnecessary vision loss.
To our knowledge, apart from those data we reported previously,7 comprehensive data on the economic impact of vision loss are not yet available for other developed countries, let alone developing areas. However, a high-level assessment of the global impact that vision impairment has on personal productivity loss of individuals has been undertaken.21 The annual global economic impact of blindness and vision loss in the year 2000 based on loss of productivity was estimated to be US$42 billion. This figure was projected to rise to $110 billion by the year 2020. If successfully implemented, the global initiative VISION 2020 was calculated to reduce this cost to US$58 billion, giving a global savings of US$223 billion over the 20 years of the program.21 Another recently published study from the Gambia has shown that the blindness prevention programs implemented in that country between 1986 and 1996 reduced the prevalence of blindness from 0.7% to 0.42%.22 These programs gave an overall internal rate of return on investment of 10%.
Taken together, these reports clearly show the importance of the global impact of blindness and vision loss. All populations from the most disadvantaged to some of the most privileged would benefit from effective eye care interventions aimed at both prevention and treatment. There clearly is an urgent need to take real national and global action to prevent and control the rising levels of unnecessary vision loss. This was addressed in the resolution of the World Health Assembly in 200323 reiterated in 2006.24 The analysis presented for Australia shows that effective and feasible interventions are not only cost effective, but cost saving.
The authors indicate no financial support or financial conflict of interest. All authors were involved in design and conduct of study; collection of data; management, analysis, interpretation, and preparation of the article; and preparation, review, and approval of the manuscript.
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Hugh R. Taylor, AC, MD, has been a Professor and Head of Ophthalmology since 1990, at the University of Melbourne, and Managing Director of the Centre for Eye Research Australia. Trained at Melbourne, he was at Johns Hopkins for 13 years. Dr Taylor has written extensively on epidemiologic and public health aspects of eye disease and is a leader in Vision 2020 and the International Council of Ophthalmology. Dr Taylor was made a Companion in the Order of Australia in 2001.
PII: S0002-9394(06)01256-6
doi:10.1016/j.ajo.2006.10.055
© 2007 Elsevier Inc. All rights reserved.
