Economic Inequality in Presenting Vision in Shahroud, Iran: Two Decomposition Methods

Economic Inequality in Visual Impairment: A Study in Deprived Rural Population of Iran

Purpose:

To determine economic inequality in visual impairment (VI) and its determinants in the rural population of Iran.

Methods:

In this population-based, cross-sectional study, 3850 individuals, aged 3–93 years were selected from the north and southwest regions of Iran using multi-staged stratified cluster random sampling. The outcome was VI, measured in 20 feet. Economic status was constructed using principal component analysis on home assets. The concentration index (C) was used to determine inequality, and the gap between low and high economic groups was decomposed to explained and unexplained portions using the Oaxaca–Blinder decomposition method.

Results:

Of the 3850 individuals that were invited, 3314 participated in the study. The data of 3095 participants were finally analyzed. The C was −0.248 (95% confidence interval [CI]: −0.347 - −0.148), indicating a pro-poor inequality (concentration of VI in low economic group). The prevalence (95% CI) of VI was 1.72% (0.92–2.52) in the high economic group and 10.66% (8.84–12.48) in the low economic group with a gap of 8.94% (6.95–10.93) between the two groups. The explained and unexplained portions comprised 67.22% and 32.77% of the gap, respectively. Among the study variables, age (13.98%) and economic status (80.70%) were significant determinants of inequality in the explained portion. The variables of education (coefficient: −4.41; P < 0.001), age (coefficient: 14.09; P < 0.001), living place (coefficient: 6.96; P: 0.006), and economic status (coefficient: −7.37; P < 0.001) had significant effects on inequality in the unexplained portion.

Conclusions:

The result showed that VI had a higher concentration in the low economic group, and the major contributor of this inequality was economic status. Therefore, policymakers should formulate appropriate interventions to improve the economic status and alleviate economic inequality.

Global, regional, and national burden of blindness and vision loss due to common eye diseases along with its attributable risk factors from 1990 to 2019: a systematic analysis from the global burden of disease study 2019

To map the magnitudes and temporal trends of blindness and vision loss (BVL) due to common eye diseases along with its attributable risk factors at the national, regional, and global levels. The annual burden of BVL in 204 countries and territories was extracted from the Global Burden of Disease Study 2019. The estimated annual percentage change (EAPC) and causes composition change were calculated to quantify the temporal trends of BVL-related disease burden by sex, region, and eye disease. The global disability-adjusted life years (DALYs) of BVL increased from 12.44 million in 1990 to 22.56 million in 2019, with a slightly decreased rate from 3.03 to 2.78 per 1000 population (EAPC = -0.30). About 29.6% of BVL-related DALYs worldwide were caused by cataract, followed by refraction disorders (29.1%), near vision loss (21.7%), other vision loss (13.7%), glaucoma (3.3%), and age-related macular degeneration (2.5%) in 2019. The age-standardized DALYs rates due to each eye disease type in most regions were decreased, especially in countries with high burden and high-middle socio-demographic index. Moreover, the contribution of smoking and air pollution from solid fuels to BVL burden decreased, however, the age-standardized burden of BVL attributed to high body-mass index and high fasting plasma glucose elevated gradually across almost all regions. The temporal trend of BVL burden due to specific eye diseases varies remarkably by region, sex and age. Understanding the real-time patterns of BVL burden is crucial for formulating more effective and targeted prevention and healthcare strategies to decrease the BVL burden.

Health equity in Iran: A systematic review

Background: Health inequities are among debatable and challenging aspects of health systems. Achieving equity through social determinants of health approach has been mentioned in most upstream national plans and acts in Iran. This paper reports the findings of a systematic review of the current synthesized evidence on health equity in Iran.

Methods: This is a narrative systematic review. The relevant concepts and terminology in health equity was found through MeSH. We retrieved the relevant studies from PubMed/MedLine, Social Sciences Database, and Google Scholar in English, plus the Jihad University Database (SID), and Google Scholar in Farsi databases from 1979 until the end of January 2018. The retrieved evidence has been assessed primarily based on PICOS criteria and then Ottawa-Newcastle Scale, and CASP for qualitative studies. We used PRISMA flow diagram and a narrative approach for synthesizing the evidence.

Results: We retrieved 172 455 studies. Following the primary and quality appraisal process, 114 studies were entered in the final phase of the analysis. The main part (approximately 95%) of the final phase included cross-sectional studies that had been analyzed through current descriptive inequality analysis indicators, analytical regression, or decomposition-based approaches. The studies were categorized within 3 main groups: health outcomes (40.3%), health utilization (32%), and health expenditures (27%).

Conclusion: As a part of understanding the current situation of health equity in the policymakers’ need to refer the retrieved evidence in this study, they need more inputs specially regarding the social determinants of health approach. It seems that health equity research plan in Iran needs to be redirected in new paths that give appropriate weights to biological, gene-based, environmental and contextbased, economic, social, and political aspects of health as well. We advocate addressing the aspects of Social Determinant of Health (SDH) in analyzing health inequalities.

Decomposing educational inequality in maternal mortality in Iran

Given the significance of educational equality as one of the key social determinants of health in maternal health outcomes, the present study aimed to assess maternal mortality inequality and its main contributors based on the level of education amongst mothers living in Isfahan, Iran. In this case-control study, all 171 maternal deaths in the Isfahan Province during 2001-2016 were taken from the national maternal mortality surveillance system (as a case group). For the control group, 523 mothers who were alive were selected from 22 health centers located in 21 cities in the province of Isfahan. Concentration index and curve were used to measure educational inequality in maternal mortality. The chi-square test was used to select explanatory social and health variables to enter the decomposition model. The analyses were performed with STATA 12. Social and healthcare factors accounted for 43.57% and 23.44% of educational inequality, respectively. The normalized maternal mortality concentration index was -0.13 (95% CI, -0.10 to -0.02). Among the social factors, the mother's education level (38.14%) and immigrant status (25.39%) contributed the most to educational inequality. Regarding healthcare factors, proximate medical causes (14.49%) and the number of pregnancies (9.72%) had the highest contribution. Maternal mortality has been distributed unequally among the less and more educated mothers in Iran, which suggests that promoting health literacy is imperative, especially for women with lower education levels.

Horizontal inequity in the utilization of cataract surgery in Iran: Shahroud Eye Cohort Study, 2009-2014

Background: Since there was no evidence about economic inequity in utilization of cataract surgery in developing countries, such as Iran, this study was designed to measure horizontal inequity in the utilization of cataract surgery and its changes in an Iranian middleaged population in 2009 and 2014. Methods: Using data from the first and second phases of Shahroud Eye Cohort Study (2009-2014), the economic inequity in the utilization of cataract surgery in an Iranian middle-aged population aged 40-64 years in 2009 and 2014 was evaluated. The horizontal inequity index (HI) was determined using the indirect standardization method based on a nonlinear (probit) model and the concentration index (C) was decomposed into the contribution of each factor. The analyses were performed using STATA software version 12/SE, and significance level was set at less than 0.05. Results: The HI in the utilization of cataract surgery increased from 0.080 (95% CI: 0.011-0.098) in 2009 to 0.166 (95% CI: 0.0821- 0.228) in 2014. Decomposition of changes in the concentration index showed that among need and non-need variables, older age and economic status (being among the wealthiest 20%) were the greatest contributors, with shares of 67.5% and 57.5%%, respectively, which led to pro-rich inequity during the study periods. Conclusion: The present study demonstrated that utilization of cataract surgery did not have an equal distribution among economic quintiles, despite considering equal needs based on cataract severity. Results demonstrated that older age and economic status were the greatest contributors to HI increase in 2009 and 2014.

The reduction of horizontal inequity in unmet refractive error: The Shahroud Eye Cohort Study, 2009-2014

Purpose

To measure Horizontal Inequity Index (HI) of unmet refractive error and its changes between 2009 and 2014 in Iran.

Methods

The data used in this study was taken from population-based study, Shahroud Eye Cohort Study. The number of participants analyzed in first (2009) and second phases of study (2014) were 5190 and 4737, respectively, and individuals between 40 and 64 years were included. The HI was determined by using the Concentration Index (C) based on the nonlinear (Probit) model, and C was decomposed to identify and quantify the contribution of each factor.

Results

After adjusting for need variables, the results demonstrated that the HI in unmet refractive need decreased from −0.288 (95% CI: 0.370, −0.206) in the 2009 to −0.132 (95% CI: 0.290, −0.028) in 2014. Decomposition of the C showed that level of education and economic status were the greatest contributors with shares of 26.2% and 17.9%, respectively, in reducing the amount of HI in unmet refractive error between 2009 and 2014.

Conclusions

The current study demonstrated that unmet refractive error did not have an equal distribution among economic quintiles, despite the same need for correcting refractive errors. Reducing the amount of HI in unmet refractive error between 2009 and 2014 indicated an improvement in the unmet need in the five years period between two phases of study.

Assessment of Horizontal Inequity in Eye Care Utilization in the Iranian Middle-aged Population

PURPOSE

The present study was designed to determine the extent that horizontal inequity was realized regarding eye care utilization in a middle-aged population as well as factors affecting this equity.

METHODS

Data were obtained from a population-based study (Shahroud Eye Cohort Study) in 2009 that included 5190 participants from 40 to 64 years of age. Horizontal inequity was determined based on the following variables: (i) economic status, (ii) eye care service needs, (iii) non-need variables, and (iv) eye care utilization (visiting an ophthalmologist or optometrist). Decomposition analysis of the concentration index based on a nonlinear model and indirect standardization was used to ascertain the contribution of each factor in inequity of eye care utilization.

RESULTS

After adjusting for need variables, the results of our study demonstrated that horizontal inequity in eye care utilization in a middle-aged Iranian population remained positive and significant (horizontal inequity: 0.19; 95% confidence interval: 0.17-0.23) indicating that use of services was focused among participants with a better financial situation. Furthermore, decomposition analysis demonstrated that educational level and economic status had the greatest contribution (54.1% and 41.1%, respectively) in comparison to other variables.

CONCLUSION

This study demonstrated that horizontal inequity exists in eye care utilization among the middle-aged Iranian population.