Factors Explaining the Change in Socioeconomic Inequality of Disability in Iran: A Repeated Cross-sectional Study

BACKGROUND: More than 15% of the world's population live with some form of disability. Assessing socioeconomic inequalities in disability and monitoring its change over time can help policymakers to design and implement targeted interventions to reduce these inequalities. This study aimed to assess the change in socioeconomic inequality in disability in Iran from 2000 to 2010. METHODS: Data for this cross-sectional study were obtained from 2 waves of Iran’s demographic and health surveys (2000 and 2010). The Wagstaff normalized concentration index was used to measure the socioeconomic inequality of disability. Contributing factors to the inequality in 2000 and 2010 were investigated by concentration index decomposition. The Blinder-Oaxaca decomposition method was used to determine contributing factors of change in disability inequality. All analyses were conducted in Stata14. RESULTS: The negative and statistically significant concentration indices (–0.132 in 2000 and –0.165 in 2010, P < 0.001) suggested more concentration of disability among poor people. The absolute value of inequality was increased by 0.034 between the 2 points of time (P = 0.025). Level of education (123.5%), household size (12.9%), age (–35.1%), and residency (in terms of Iran's provinces) (–19.3%) were the contributing factors to the measured disability inequality in 2000. In 2010, level of education (105.8%), household size (30.5%), and urban residency (–46.3%) explained the measured inequality. Change in disability inequality was explained by household size (99.4%), province of residence (54.8%), education (36.9%), socioeconomic status (20%), urban residency (–90.3%), and age (–47.7%). CONCLUSION: Iran suffers from significant socioeconomic inequality in disability, and it significantly increased over time. Interventions such as increasing health literacy and providing suitable job opportunities for people with low education level, improving the socioeconomic status of extended households, and paying more attention to the balanced development in the provinces and urban and rural areas, and attending to prevention, treatment, and mitigation of disability adversities among poor young and elderly people could be recommended to tackle increased socioeconomic inequality in disability and its unfavorable consequences in Iran.