عوامل مؤثر بر مرگ و صدمات در ارتباط مستقیم با زلزله 5 دی‌ماه 1382 بم

Background & Objectives: The widely differing casualty rates in earthquakes of similar magnitude indicate a need for assessing the factors that determine the extent of damage to life and property. The present study looks at the structural factors and individual characteristics that had an effect on the risk of death and injury directly caused by the December 2003 earthquake in Bam. Methods: The study population consisted of the residents of Bam on the 19th and 20th days after the earthquake of December 25, 2003. Using a cluster sampling method based on geographic location, we selected 420 households for study and asked them for information on the family members who were inside their houses at the time of the quake. The information covered the following range of items: occurrence of death or injury leading to ambulatory treatment or hospitalization, and characteristics of the building. We used logistic regression and the software package Stata 8.0 for data analysis. Results: A total of 2089 individuals, including 1089 men (52.1%) and 1000 women (47.9%) took part in this study. There were 369 cases of death (17.7%, 95%CI=12.6-17.8%), 122 injuries needing hospitalization (5.8%, 95%CI=4.5-7.1%), and 319 cases of injury treated on an ambulatory basis (15.3%, 95%CI=12.6-17.8%), all as a direct result of the earthquake. Factors associated with increased risk of death were building destruction (OR=6.34, 95%CI=3.56-11.29), living in adobe structures (OR=1.87, 95%CI =1.03-3.4), age under 6 years (OR=3.93, 95%CI=2.17-7.11) and age 56-65 years (OR=2.52, 95%CI=1.23-5.15). Risk factors for injuries were the same as for death, with the notable exception of the building material. Conclusions: This was the first analytic study of the risk factors for earthquake-related deaths in Iran. It revealed that total building destruction, residing in houses built with non-resistant materials, and extremes of age are significant risk factors for death in an earthquake. As for injuries, the risk factors were total building destruction and extremes of age.