Cost of myopia correction: a systematic review

Authors: Foo LL, Lanca C, Wong CW, Ting D, Lamoureux E, Saw S-M and Ang M.

Geographical coverage: USA, Spain, Iran, Singapore, Iran

Sector: Impact / economic evaluation

Sub-sector: Cost

Equity focus: None

Study population: Not applicable; review sought to examine costs of myopia treatment. 

Review type: Other review

Quantitative synthesis method: Systematic review

Qualitative synthesis method: Not applicable

Background: Myopia is one of the leading causes of visual impairment globally. Despite increasing prevalence and incidence, the associated cost of treatment remains unclear. Health care spending is a major concern in many countries and understanding the cost of myopia correction is the first step alluding to the overall cost of myopia treatment. As cost of treatment will reduce the burden of cost of illness, this will aid in future cost-benefit analysis and the allocation of health care resources, including considerations in integrating eye care (refractive correction with spectacles) into universal health coverage (UHC).

Objectives: To determine the economic costs of myopia correction.

Main findings:

Overall, authors found that the annual prevalence-based direct costs for myopia correction are substantial, ranging from US$14-26 (USA), $56 (Iran) to $199 (Singapore) per capita.

Five eligible full text articles were included in this review. The Asian studies were comprised of two from Singapore while the non-Asian studies comprised one from the United States of America (USA), one from Iran and one from Spain. Of the included studies, four were good in quality and one was excellent. The interrater-reliability κ was moderate in one study, substantial in two studies and perfect in two studies.

Costs related to myopia correction were mainly direct with few indirect costs. Annual prevalence-based direct costs for myopia ranged from $14-26 (USA), $56 (Iran) and $199 (Singapore) per capita, respectively (population: 274.63 million, 75.15 million and 3.79 million, respectively). The per capita annual cost of myopia correction was low in the USA, moderate in Iran and high in Singapore. Annually, the direct costs of contact lenses were $198.30-$378.10, while spectacles and refractive surgeries were $342.50 and $19.10, respectively. Indirect costs in myopia correction are mainly related to complications, particularly with contact lens use, including cost of treatment, loss of productivity secondary to complications and its associated travel costs.

Without further interventions, the economic burden of illness of myopia will increase substantially with the projected increase in prevalence worldwide. Hence, myopia control treatment in children and measures to prevent myopia and high myopia will play an increasingly important role to reduce prevalence and costs of illness.

Future studies will be necessary to generate a more homogenous cost data and provide a more complete picture of the global economic cost of myopia treatment. These include cost of illness analysis, programmatic costs of spectacles correction in rural areas by non-governmental organisations and cost-effectiveness randomised control trials of treatments for myopia progression.

Methodology:

Inclusion criteria consisted of original full-text articles in English if costs were quantified in relation to myopia correction, including myopia correction (spectacles, contact lenses, refractive surgeries).

Authors searched several electronic databases including PubMed, ScienceDirect, Cochrane Library, and Web of Science databases, to identify English language articles up to 29 February 2020 on costs associated with myopia correction treatment. Searches used the keywords “myopia”, “short-sightedness” or “near-sightedness” combined with “cost” or “economic burden”.

A 20-items Consensus Health Economic Criteria (CHEC) extended checklist was used to evaluate the overall quality of included studies. Only moderate, good and excellent quality studies were included, as higher scores denote lower risk of bias. Two independent reviewers conducted the assessment and the interrater-agreement was evaluated using κ from Stata/IC 11.1.

Applicability/external validity: The authors acknowledged several limitations that could potentially affect the reliability of their findings. Distinguishing between the costs of optometry visits and refractive correction devices for myopia correction proved challenging due to variations in the methodologies of the studies. The presence of recall and non-response biases from retrospective design studies and the use of questionnaires/interviews was another limitation. Furthermore, the cost data from older studies may not accurately reflect current costs due to various economic factors. The details of indirect costs were not adequately provided. Lastly, the limited number of studies available in the literature and their limited global representation were also noted as limitations.

Geographic focus: Search was unrestricted in terms of country, but only studies from four countries, including one from Iran were included.

Summary of quality assessment:

Certain aspects of the approach to evaluate, include, and critically assess studies were robust, with two authors conducting the search, data extraction, and quality assessment. However, the search was somewhat restricted, as it only included English texts, did not involve checks on reference lists of identified items, and did not include unpublished material. Furthermore, it’s unclear if there was a cut-off for the search in terms of publication date. While the approach to the descriptive analysis of the data was rigorous, it’s worth noting that only five studies were included, these yielded highly varied results, and they covered a very limited geographic area. For these reasons, the findings of this review are regarded with low confidence.