Social and ophthalmic factors influencing prescribing patterns for childhood myopia
Lead Research Organisation:
Queen's University Belfast
Department Name: Centre for Public Health
Abstract
Education is a major driver of life chances in developed societies. There are strong associations between high educational attainment and improved employment prospects, increased income and raised socio-economic status. Education is the engine of social mobility and the earliest years are most important. It is known that educational deficits emerge early in children's lives, and widen throughout childhood.
One factor that has received little attention in the UK is the influence of poor eyesight on educational attainment. Poor eyesight can dramatically reduce the educational potential of children. The most common cause of visual impairment is uncorrected refractive error, where the shape of the eye does not focus light onto the retina correctly, producing a blurred image. Children with uncorrected myopia (near-sight) may struggle to see the blackboard and long-sighted children have difficulty reading. Myopia is the most common form of refractive error and can be corrected simply with spectacles; trials have shown that this can lead to improved educational attainment. However, it is likely that social factors prevent some UK children from receiving spectacle correction in a timely manner, potentially jeopardising their education. The ways in which social factors influence myopia detection, correction and hence educational attainment in the UK are unknown and these areas form the focus of this study.
In the UK, myopia is managed by community optometrists. School age children are eligible to receive free annual sight tests and it is here that myopia is frequently diagnosed. However, sight test attendance is voluntary and so myopia will remain undetected for as long as parents do not present their children for testing. Uptake rates of child sight testing are unknown but based on previous research into other child health services (especially dentistry) there are likely to be strong social gradients favouring the more affluent. Hence, delayed correction of myopia may be one of the factors behind social gradients in educational attainment.
One way to reduce disparities in uptake of child sight tests would be to screen schoolchildren for myopia, disconnecting attendance from parental attitudes and behaviours. Children are currently screened for early-developing sight problems such as lazy eye either pre-school or on school entry but this is too early to detect the majority of myopia cases. In one strand of this study we will build a mathematical model to assess whether screening for myopia would be cost-effective for reducing social gradients in unmet need for spectacles.
In this study we will use the facilities of the Administrative Data Research Centre - Northern Ireland to securely link three large administrative (government) databases for the first time: records of all NHS sight tests and spectacle prescriptions for children (2009-2016); educational attainment at age 16 drawn from the School Leavers Survey; detailed family structure, social and economic information drawn from the 2011 Census. We will consider a range of factors including sex, ethnicity, parental educational attainment and socio-economic status, urban/rural location, distance to optometrists and family history of myopia.
We will use the linked data to address three main research questions: a) Which social and economic factors are associated with uptake of child sight tests and timing of myopia correction? b) Is timing of myopia correction associated with subsequent educational attainment at age 16? c) Under what conditions would screening of schoolchildren for myopia be cost-effective?
We envisage two main practical benefits: improved care for children with myopia and better evidence to target NHS sight test services. We will share our results and work closely with policy makers, optometry organisations and other stakeholders to ensure that myopic children in the UK have the best possible management of their condition and educational prospects.
One factor that has received little attention in the UK is the influence of poor eyesight on educational attainment. Poor eyesight can dramatically reduce the educational potential of children. The most common cause of visual impairment is uncorrected refractive error, where the shape of the eye does not focus light onto the retina correctly, producing a blurred image. Children with uncorrected myopia (near-sight) may struggle to see the blackboard and long-sighted children have difficulty reading. Myopia is the most common form of refractive error and can be corrected simply with spectacles; trials have shown that this can lead to improved educational attainment. However, it is likely that social factors prevent some UK children from receiving spectacle correction in a timely manner, potentially jeopardising their education. The ways in which social factors influence myopia detection, correction and hence educational attainment in the UK are unknown and these areas form the focus of this study.
In the UK, myopia is managed by community optometrists. School age children are eligible to receive free annual sight tests and it is here that myopia is frequently diagnosed. However, sight test attendance is voluntary and so myopia will remain undetected for as long as parents do not present their children for testing. Uptake rates of child sight testing are unknown but based on previous research into other child health services (especially dentistry) there are likely to be strong social gradients favouring the more affluent. Hence, delayed correction of myopia may be one of the factors behind social gradients in educational attainment.
One way to reduce disparities in uptake of child sight tests would be to screen schoolchildren for myopia, disconnecting attendance from parental attitudes and behaviours. Children are currently screened for early-developing sight problems such as lazy eye either pre-school or on school entry but this is too early to detect the majority of myopia cases. In one strand of this study we will build a mathematical model to assess whether screening for myopia would be cost-effective for reducing social gradients in unmet need for spectacles.
In this study we will use the facilities of the Administrative Data Research Centre - Northern Ireland to securely link three large administrative (government) databases for the first time: records of all NHS sight tests and spectacle prescriptions for children (2009-2016); educational attainment at age 16 drawn from the School Leavers Survey; detailed family structure, social and economic information drawn from the 2011 Census. We will consider a range of factors including sex, ethnicity, parental educational attainment and socio-economic status, urban/rural location, distance to optometrists and family history of myopia.
We will use the linked data to address three main research questions: a) Which social and economic factors are associated with uptake of child sight tests and timing of myopia correction? b) Is timing of myopia correction associated with subsequent educational attainment at age 16? c) Under what conditions would screening of schoolchildren for myopia be cost-effective?
We envisage two main practical benefits: improved care for children with myopia and better evidence to target NHS sight test services. We will share our results and work closely with policy makers, optometry organisations and other stakeholders to ensure that myopic children in the UK have the best possible management of their condition and educational prospects.
Planned Impact
Two main benefits are expected to stem from this study: improved care for children with myopia and improved evidence to inform commissioning of General Ophthalmic Services in Northern Ireland.
Improving care for myopic children:
If the study reveals evidence of unmet need for myopic correction this may lead to interventions to increase the proportion of myopic children receiving timely spectacle correction. Timely correction is likely to make daily tasks easier leading to improved quality of life in the medium term. If delayed myopic correction is associated with reduced educational attainment at age 16 then timely correction may lead to long term improvements in employment prospects, increased income and socio-economic status. Timely correction could also bring health benefits in adulthood, reducing myopia progression and risk of sight threatening conditions including cataract and glaucoma.
The project is designed to investigate which individual, household and area level socio-economic factors are most strongly associated with timely correction and hence indicate the most profitable areas for intervention.
The project may identify socio-economic groups in which sight tests are sought only once myopia has progressed substantially. Interventions to increase uptake could be targeted towards these groups and the strength of associations between socio-economic factors and uptake may indicate the key barriers. Programmes to address these barriers would be likely to involve multiple agents, including optometrists, other healthcare and education professionals and social workers. The research team will work with regional agencies such as the Northern Ireland Optometric Society and the Health and Social Care Board to develop targeted materials or information for practitioners and patients, highlighting the importance of sight tests for children. Provision of updated guidelines through the continuing education and training (CET) programme for optometrists (through the UK College of Optometrists) will form a key part of this strategy.
Informing eye care policy:
The project will describe the changing patterns of myopia in Northern Ireland in unprecedented detail. These findings will provide insight into expected future demand for sight testing and myopia correction; policy relevant information for the Health and Social Care Board when planning and budgeting for General Ophthalmic Services (sight tests and spectacle vouchers) in the medium term. Given the increasing evidence for a link between myopia and risk of cataract, maculopathy, retinal detachment and glaucoma in later life, the study may also inform longer term planning for the Health Trusts tasked with managing and treating these conditions.
The third strand of the project will give an insight into the implications of active screening for myopia instead of the current surveillance policy. It will provide a quantitative assessment of the cost effectiveness of screening, vital information for policy makers considering the benefits of this potential policy shift.
Improving care for myopic children:
If the study reveals evidence of unmet need for myopic correction this may lead to interventions to increase the proportion of myopic children receiving timely spectacle correction. Timely correction is likely to make daily tasks easier leading to improved quality of life in the medium term. If delayed myopic correction is associated with reduced educational attainment at age 16 then timely correction may lead to long term improvements in employment prospects, increased income and socio-economic status. Timely correction could also bring health benefits in adulthood, reducing myopia progression and risk of sight threatening conditions including cataract and glaucoma.
The project is designed to investigate which individual, household and area level socio-economic factors are most strongly associated with timely correction and hence indicate the most profitable areas for intervention.
The project may identify socio-economic groups in which sight tests are sought only once myopia has progressed substantially. Interventions to increase uptake could be targeted towards these groups and the strength of associations between socio-economic factors and uptake may indicate the key barriers. Programmes to address these barriers would be likely to involve multiple agents, including optometrists, other healthcare and education professionals and social workers. The research team will work with regional agencies such as the Northern Ireland Optometric Society and the Health and Social Care Board to develop targeted materials or information for practitioners and patients, highlighting the importance of sight tests for children. Provision of updated guidelines through the continuing education and training (CET) programme for optometrists (through the UK College of Optometrists) will form a key part of this strategy.
Informing eye care policy:
The project will describe the changing patterns of myopia in Northern Ireland in unprecedented detail. These findings will provide insight into expected future demand for sight testing and myopia correction; policy relevant information for the Health and Social Care Board when planning and budgeting for General Ophthalmic Services (sight tests and spectacle vouchers) in the medium term. Given the increasing evidence for a link between myopia and risk of cataract, maculopathy, retinal detachment and glaucoma in later life, the study may also inform longer term planning for the Health Trusts tasked with managing and treating these conditions.
The third strand of the project will give an insight into the implications of active screening for myopia instead of the current surveillance policy. It will provide a quantitative assessment of the cost effectiveness of screening, vital information for policy makers considering the benefits of this potential policy shift.
Organisations
Publications
Eriksson E
(2020)
Pain in children and adolescents with cerebral palsy - a cross-sectional register study of 3545 individuals.
in BMC neurology
NCD Risk Factor Collaboration (NCD-RisC)
(2020)
Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants.
in Lancet (London, England)
NCD Risk Factor Collaboration (NCD-RisC)
(2020)
Repositioning of the global epicentre of non-optimal cholesterol.
in Nature
| Description | The project did not meet the original objectives because access to the data on which it was founded was delayed excessively, and when data were made available, they were found to have significant unforeseen limitations. The main limitation was that one of the key variables needed to diagnose myopia was inconsistently recorded in a substantial portion of the dataset. For the first five years of the data series, the sign (+ or -) of measurements was not recorded, making it impossible to determine which prescriptions were for myopia and hence track disease progression or estimate prevalence changes over time. There is evidence that data quality has improved over time (probably due to a switch from paper-based to electronic data collection). However, this artefact in the data has effectively closed off research into myopia using these data until sufficient high quality records have accumulated (likely to take several more years). |
| Exploitation Route | The main recommendation stemming from this project is that services offering access to administrative data for research be radically reformed so that data are made available within a reasonable and defined timescale. The long and unexplained delays in access to pre-existing data experienced during this project ultimately led to its failure. A key service improvement would be development of a graded system by which small and unlinked datasets could be accessed quickly (perhaps within three months using a single streamlined application form). This 'sandbox' approach would enable researchers to establish the strengths and limitations of new datasets, (including assessing quality of key variables) before investing time in governance and funding applications for larger and more complex linkages. This would increase the chances that the eventual dataset would be fit for the proposed project . Another recommendation is that access to administrative data for research should be pivoted away from the physical 'Secure Research Environment' model wherever possible. The delay of 11 months in this project due to Covid-19 restrictions would not have occurred if a remote access solution had been in place. |
| Sectors | Other |
| Description | The main anticipated impact from this research will result from feedback to public sector data custodians and processors on quality and access issues relating to the data sources used. This project centred on a linkage between two large administrative (government) databases held by the Business Services Organisation (BSO) and the Northern Ireland Statistics and Research Agency (NISRA). Ultimately, the project failed to achieve its stated aims because of delays in access to the linked data and also due to poor data quality in some parts of the BSO dataset that was substantial enough to prevent meaningful analysis. This is a risk inherent to this type of project, where data is used for a purpose for which it was not originally intended. We will prepare a short report to the data custodians, outlining the issues with the data, detailing the time periods and variables for which records are of low quality. Our research indicated that quality has improved over time, likely as a result of migration from a paper-based to an entirely electronic system of data collection at BSO. Feeding back information in this way will enable the data custodians and any future prospective users of the data to produce statistics and design studies appropriate to the limitations of the source data. |
| First Year Of Impact | 2022 |
| Sector | Other |
| Description | Presentation to senior Departmental policy makers of ADR NI's research priorities |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Policymakers/politicians |
| Results and Impact | as per title |
| Year(s) Of Engagement Activity | 2021 |