Health inequalities exist where people receive different levels of health care to others, resulting in outcomes like reduced life expectancy and quality of life.
These inequalities exist within eye health, and research has shown that there are population groups currently underserved by existing eye care services, such as rural dwellers, women, and indigenous people.
Eye health surveys are a useful tool for improving eye care, but it is unknown as to whether disadvantaged groups are currently included properly in these analyses.
A new study by the International Centre for Eye Health and the University of Auckland has found that underserved groups could be better considered within population-based eye health surveys.
Reviewing surveys published since the year 2000, the authors found 388 that measured vision impairment or blindness. The researchers then assessed whether the studies considered disadvantaged groups across 15 stages of the survey process using the PROGRESS+ framework, a system which identifies and classifies population groups.
They found that few studies prospectively considered underserved groups during study planning or implementation. For example, less than 1% considered such groups while calculating who would be included in the survey sample size, and only 18% included considerations around these groups when recruiting for the survey.
Nearly all surveys however did consider underserved groups after the data was collected (for example, by comparing the number of people with vision loss in rural vs urban locations). Despite few studies including them in their design, 43% were conducted primarily on underserved population groups themselves, particularly subnational studies and those focused on rural dwellers.
Generally, the study found that national level surveys disaggregated prevalence estimates by at least one PROGRESS + factor to illustrate disparities between large population groups (for example, men and women, or geographic regions within a country). However, smaller population groups, such as people without housing, incarcerated people, and refugees, arguably among the most underserved groups, were not included at all in national surveys.
The authors give several recommendations for improving representation in these surveys, including conducting surveys that consider these groups from the early survey planning stages and increasing the sample size in national surveys to ensure sufficient statistical power is reached for comparisons between subgroups.
With active inclusion of underserved groups, countries could in the future have access to national data describing vision impairment and service coverage among large population groups (e.g. regions, men and women, urban and rural dwellers) while also having data for the most marginalized and socially excluded, which would likely come from smaller-scale studies. Together this could help to improve eye care coverage for all.
Publication
Goodman L, Reis T, Zhang JH, Yusufu M, Turnbull PR, Silwal P, et al. Underserved groups could be better considered within population-based eye health surveys: a methodological study. Journal of Clinical Epidemiology. September 2024. 173:111444. https://doi.org/10.1016/j.jclinepi.2024.111444