Background: Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a newly identified coronavirus. Our knowledge about survival rate and prognostic factors of the disease is not established well. This study proposed to estimate the survival function of COVID-19 in western Iran.Methods: This retrospective cohort study was performed in Hamadan province, western Iran. The study included patients that referred to the provincial hospitals during 7 months period from February 20 to September 20, 2020. The follow up of each subject was calculated from the date of onset of respiratory symptoms to the date of death. Demographic and clinical data were extracted from patients’ medical records. Kaplan-Meier method, log-rank test, and Cox regression were used for the analysis of the data. Results: The overall 1, 5, 10, 20, 30 and 49-day survival rate were 99.57%, 95.61%, 91.15%, 87.34%, 86.91%, and 86.74% respectively. A significant association was observed between survival time with age, gender, history of traveling to contaminated areas, co-morbidity, malignancies, and chronic diseases, and hospital units.Conclusion: Educational programs and access to healthcare could be implemented as modifiable factors to reduce the mortality rate and burden of this disease in COVID-19 patients.

The analytical functions that we obtained from fitting process in Monte Carlo data can be used for obtaining the absorbed fractions of iodine-131 beta and gamma rays for any volume of the thyroid lobe. Moreover, our results for the spheres are in good agreement with the results of MIRD and other scientific literatures.