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<h5 class="section-title" id="d9649927e323">Importance</h5>
<p id="d9649927e325">Vision loss is the third most common impairment worldwide. Although
cost-effective
interventions are available for preventing or curing most causes of vision loss, availability
of these interventions varies considerably between countries and districts. Knowledge
of the association between vision loss and socioeconomic factors is informative for
public health planning.
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<h5 class="section-title" id="d9649927e328">Objectives</h5>
<p id="d9649927e330">To explore correlations of the prevalence of visual impairment
with socioeconomic
factors at country levels and to model and estimate a socioeconomic-adjusted disease
burden based on these data.
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<h5 class="section-title" id="d9649927e333">Design, Setting, and Participants</h5>
<p id="d9649927e335">In this cross-sectional study, the following data were collected
from 190 countries
and territories: the age-standardized prevalence of moderate to severe visual impairment
(MSVI) and blindness from January 1 to December 31, 2010, across countries, human
development index (HDI), gross domestic product (GDP) per capita, total health expenditure,
total health expenditure as percentage of GDP (total health expenditure/GDP), public
health expenditure as percentage of total health expenditure (public/total health
expenditure), and out-of-pocket expenditure as percentage of total health expenditure
(out-of-pocket/total health expenditure). Countries were divided into 4 levels (low,
medium, high, and very high) by HDI. Data analysis was conducted from September 1,
2016, to July 1, 2017.
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<h5 class="section-title" id="d9649927e338">Main Outcomes and Measures</h5>
<p id="d9649927e340">The correlations between prevalence data and socioeconomic indices
were assessed.</p>
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<h5 class="section-title" id="d9649927e343">Results</h5>
<p id="d9649927e345">A strong negative association between prevalence rates of MSVI
and blindness and socioeconomic
level of development was observed. The mean (SD) age-standardized prevalence of MSVI
decreased from 4.38% (1.32%) in low-HDI regions to 1.51% (1.00%) in very-high-HDI
regions (
<i>P</i> < .001). The national HDI level was attributable to 56.3% of global variation
in
prevalence rates of MSVI and 67.1% of global variation in prevalence rates of blindness.
Higher prevalence rates were also associated with lower total health expenditure per
capita, total health expenditure/GDP (β = −0.236 [95% CI, −0.315 to −0.157] for prevalence
of MSVI; β = −0.071 [95% CI, −0.100 to −0.042] for prevalence of blindness), public/total
health expenditure (β = −0.041 [95% CI, −0.052 to −0.031] for prevalence of MSVI;
β = −0.014 [95% CI, −0.018 to −0.010] for prevalence of blindness), and higher percentage
of out-of-pocket/total health expenditure (β = 0.044 [95% CI, 0.032-0.055] for prevalence
of MSVI; β = 0.013 [95% CI, 0.009-0.017] for prevalence of blindness). Countries with
increased burden of visual impairment and blindness can be easily identified by the
results of the linear models. Socioeconomic factors could explain 69.4% of the global
variations in prevalence of MSVI and 76.3% of the global variations in prevalence
of blindness.
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<h5 class="section-title" id="d9649927e351">Conclusions and Relevance</h5>
<p id="d9649927e353">Burden of visual impairment and socioeconomic indicators were
closely associated and
may help to identify countries requiring greater attention to these issues. The regression
modeling described may provide an opportunity to estimate appropriate public health
targets that are consistent with a country’s level of socioeconomic development.
</p>
</div><p class="first" id="d9649927e356">This cross-sectional study explores correlations
of the prevalence of visual impairment
with socioeconomic factors at country levels and models and estimates a socioeconomic-adjusted
disease burden based on these data.
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<h5 class="section-title" id="d9649927e362">Question</h5>
<p id="d9649927e364">What is the association between the burden of visual impairment
and national level
of socioeconomic development?
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<h5 class="section-title" id="d9649927e367">Findings</h5>
<p id="d9649927e369">In this cross-sectional study, socioeconomic factors explained
69.4% of global variations
in moderate to severe visual impairment and 76.3% of global variations in prevalence
of blindness.
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<h5 class="section-title" id="d9649927e372">Meaning</h5>
<p id="d9649927e374">The close association of burden of visual impairment and socioeconomic
indicators
may help to identify countries requiring greater attention; regression modeling also
provides an opportunity to estimate appropriate public health targets that are consistent
with a country’s level of socioeconomic development.
</p>
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