Inequality of Leprosy Disability in Iran, Clinical or Socio-Economic Inequality: An Extended Concentration Index Decomposition Approach

BACKGROUND Despite significant reduction in global disease prevalence, leprosy still has a high rate of disability while its determinants are unfair and many of them are amendable. The objective of this study was to measure inequality of disability in leprosy in Iran. METHODS This was a cross-sectional study (2006-2007) on all living people affected by leprosy registered in W. Azerbaijan province health center, Western North of Iran. The outcome of the study was the socio-economic inequality considering presence or absence of grade 2 disability (G2D) based on the WHO classifications. An extended concentration index decomposition approach was used for analysis. RESULTS Among 452 cases, 65.3% were male and 67% were affected by the multi bacillary type. Overall G2D was 65.3%. The estimated Concentration Index was -0.0782, showing presence of pro-poor socio-economic inequality of G2D, while extended CI estimation (ѵ = 5) was -0.163. Achievement index with coefficient (ѵ = 5) revealed that G2D mean was 16% more than classic mean in the poorest group. The result of decomposition of the existing inequality revealed that, some of the determinants such as receiving mono-therapy, education, urbanization, and bacillus calmette guerin (BCG) vaccination had shared contribution (67.4%, 61.8%, 59.2%, and 57.5% respectively). CONCLUSIONS This study provided new perspective for the health system to leprosy control considering the significant gap between rich and poor (inequality) regarding G2D disability, and its effective elements in socio-economic strata. Some effective actions can be considered to reduce the scale of existing inequality.