Background and purpose: Due to the difficulty of diagnosis, esophageal and gastric cancers have a special position in Mazandaran Province. Ïn this province, gastric cancer is considered to be one the most important causes of mortality therefore, this study was conducted to investigate the survival of patients with gastric cancer in Mazandaran. Materials and methods: Ïn this historical Çoho...

Background and Aim: Thyroid cancer is one of the most common endocrine system cancer and rare types of cancers. However, despite to low death rate, the prevalence of this disease is high. Different factors affected on incident, recurrence and death in thyroid cancer patients. This study aimed to identify these factors. Method: In this historical cohort study, 631 cases of thyroid cancer referr...

Introduction: The most important models used in analysis of survival data is proportional hazards models. Applying this model requires establishment of the relevance proportional hazards assumption, otherwise it world lead to incorrect inference. This study aims to evaluate Cox and Weibull models which are used in identification of effective factors on survival time in acute leukemia. Me...

‎By existing censor and skewness in survival data‎, ‎some models such as weibull are used to analyzing survival data‎. ‎In addition, parametric and semiparametric models can be obtained from baseline hazard function of Cox model to fit to survival data‎. ‎However these models are popular because of their simple usage but do not consider unknown risk factors‎, ‎that's why cannot introduce the be...