The age and cause decomposition of inequality in life expectancy between Iranian provinces: application of Arriaga method

BACKGROUND: This study aimed to decompose the age and cause inequality in life expectancy between two Iranian provinces with the highest and the lowest life expectancy using the Arriaga method. METHODS: The required data was extracted from the death registration system (DRS) and statistical center of Iran. First, we calculated life expectancy at birth for 31 provinces of Iran using life tables, and subsequently, two provinces with the highest and the lowest life expectancy were determined. To decompose the age and cause share in the life expectancy gap between the two provinces, we used Arriaga's method. RESULTS: Tehran with 80.09 years and Sistan and Baluchistan with 72.9 years had the highest and the lowest life expectancy among Iranian Provinces respectively. As a result, the life expectancy gap between Tehran and Sistan and Baluchistan was 7.19 years. Results of age decomposition showed that the highest share in the life expectancy gap attributed to the age group under one year (1.25 years). In terms of the cause of death, the highest percentage belonged to hypertensive diseases with a share of 1.77 years. CONCLUSIONS: There is a wide gap between two provinces with the highest and the lowest life expectancy. Age less than one year and hypertensive diseases were major factors in this inequality. Therefore, policy-makers should concentrate on improvement of survival in children and the reduction of hypertensive diseases to promote life expectancy in Sistan and Baluchistan.