Trend of Appendicitis Mortality at National and Provincial Levels in Iran from 1990 to 2015

Background: Appendicitis is one of the most preventable causes of death worldwide. We aimed to determine the trend of mortality due to appendicitis by sex and age at national and provincial levels in Iran during 26 years. Methods: Data were collected from Iran Death Registration System (DRS), cemetery databanks in Tehran and Esfahan, and the national population and housing censuses of Iran. The estimated population was determined for each group from 1990 to 2015 using a growth model. Incompleteness, misalignment, and misclassification in the DRS were addressed and multiple imputation methods were used for dealing with missing data. ICD-10 codes were converted to Global Burden of Disease (GBD) codes to allow comparison of the results with the GBD study. A Spatio-temporal model and Gaussian Process Regression were used to predict the levels and trends in child and adult mortality rates, as well as cause fractions. Results: From 1990 to 2015, 6,982 deaths due to appendicitis were estimated in Iran. The age-standardized mortality rate per 100000 decreased from 0.72 (95% UI: 0.46-1.12) in 1990 to 0.11 (0.07-0.16) in 2015, a reduction of 84.72% over the course of 26 years. The male: female ratio was 1.13 during the 26 years of the study with an average annual percent change of -2.31% for women and -2.63% for men. Among men and women, appendicitis mortality rate had the highest magnitude of decline in the province of Zanjan and the lowest in the province of Hormozgan. In 1990, the lowest age-standardized appendicitis-related mortality was observed in both women and men in the province of Alborz and the highest mortality rate among men were observed in the province of Lorestan. In 2015, the lowest mortality rates in women and men were in the province of Tehran. The highest mortality rates in women were in Hormozgan, and in men were in Golestan province. Conclusion: The mortality rate due to appendicitis has declined at national and provincial levels in Iran. Understanding the causes of differences across provinces and the trend over years can be useful in priority setting for policy makers to inform preventive actions to further decrease mortality from appendicitis.