Document Type : Original Article
Authors
1
National Center for Health Insurance Research, Tehran, Iran
2
School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
3
Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
4
Department of Biostatistics and Epidemiology, School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran
5
Department of Community Medicine, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
6
Department of Global Health and Public Policy, School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran
7
Department of Health Management, Policy and Economics, School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran
8
Health Equity Research Centre (HERC), Tehran University of Medical Sciences (TUMS), Tehran, Iran
Abstract
Background
Diabetic retinopathy (DR) is a major microvascular complication of diabetes. Given its growing global burden and research inequities, we examined how national DR burden and socioeconomic factors relate to research interest (RI) in DR across low- and middle-income countries (LMICs) and high-income countries (HICs).
Methods
We retrieved peer-reviewed DR articles published between 2018 and 2022 from Scopus. Spearman’s correlation test and multivariable linear regression were used to assess the associations between the independent variables: (a) socioeconomic factors, including health expenditure per capita purchasing power parity (PPP), current health expenditure (% of gross domestic product [GDP]), research and development (R&D) index, and human development index (HDI); (b) age-standardized years lived with disability (YLDs) rates of DR-related moderate (moderate vision impairment, MVI) and severe vision impairment (SVI) and blindness; and (c) disability-adjusted life years (DALYs) rate for diabetes, with our outcome variable, DR RI, calculated as the ratio of the number of DR publications in the field of medicine and life sciences to the whole output in the same field and country. Sensitivity analyses (2020-2022 RI vs. 2018-2019 burden) were conducted to address temporality.
Results
In HICs, after adjustment for socioeconomic factors and DR-specific burden (MVI, SVI, or blindness, modeled separately), the diabetes DALY rate was the only variable independently associated with RI: MVI (β = 0.56, 95% CI: 0.16 to 0.95), SVI (β = 0.57, 95% CI: 0.19 to 0.94), and blindness (β = 0.61, 95% CI: 0.21 to 1.02). In LMICs, no significant relationships were found between RI and MVI, SVI, blindness or diabetes DALY rates. These findings remained consistent in sensitivity analyses.
Conclusion
Our research demonstrates that there is a lack of significant correlation between research efforts and the burden of DR, particularly among LMICs, which may highlight the need to strengthen research infrastructure and realign national health research priorities.
Keywords
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