Investigation of Economic Inequality in Eye Care Services Utilization and Its Determinants in Rural Regions Using the Oaxaca- Blinder Decomposition Approach.

Purpose: This study was conducted to determine economic inequality in Eye Care Services Utilization (ECSU) and its determinants in the underserved rural population of Iran.
Methods: In this population-based study, two underserved regions in the north and southwest of Iran were randomly selected and 3850 individuals living in these regions were invited to participate in the study. ESCU was defined as a history of at least one optometric or ophthalmologic visit during the lifetime. Concentration index (C) was used to evaluate economic inequality and the Oaxaca- Blinder decomposition was applied to decompose the gap between the rich and poor.
Results: Of 3851 individuals, 3314 participated in the study (response rate: 86%). The data of 3094 participants were analyzed. The concentration index was 0.139 (95% CI: 0.218 - 0.590), indicating a pro-rich inequality in the ECSU. The ECSU was 12.38% (10.46 to 14.31) in the poor and 21.15% (18.38 to 23.92) in the rich, and the gap between them was about 90% in favor of the rich ( p < 00.001). A marked percentage of the gap was due to the explained portion (b: -11.49; p < .001). The unexplained portion coefficient was b: 2.72 (p: 0.020). In the explained portion, economic status (b: -12.37; p < .001) and age (b: 0.90; p: 0.021) caused inequality in favor of the rich and poor respectively while only economic status (b:-21.1; p < .001) had a significant effect on inequality in favor of the rich in the unexplained portion.
Conclusion: There is a significant pro-rich inequality in ECSU in the rural areas of Iran. A major portion of this inequality is related to differences in age and economic status between the two groups. Economic status has direct and indirect effects on inequality in ECSU; therefore, health policymakers should focus on economic improvement to remove the gap.