the waiting time between children births are called tempo. this phenomenon plays a crucial role in the child and mother health. the purpose of the present study is determination of factors which influence this variable of interest. a significance level of 5% and power of 80% considered to calculate the required sample size for this cross sectional study. the sample size of 124 women determined ...

objective: tempo is the average waiting time to next birth for a woman. role of fertility as the most important phenomenon determining population fluctuations due to the studies of it compared with other demographic phenomena be important and review the multifarious socioeconomic factors of it share  a large effective population studies. general purpose of this study is fitting the cox model to...

background: cox proportional hazard (cph) model is the most widely used model for survival analysis. when there are unobserved/unmeasured individuals factor, then the results of the cox proportional hazard model may not be reliable. the purpose of this study was to compare the results of cph and frailty models in breast cancer (bc) patients. methods: a historical cohort study was carried out us...

this study was designed to investigate causes of culling in industrial dairy herds in fars province and to describe the pattern of reason-specific culling with respect to age of animal and interval from calving to culling. a total number of 9 dairy herds were selected for the study and information about culling reasons, birth date, last calving date and culling date was collected for culled cow...

background: the aim of this study is to evaluate the association between different treatments and survival time of breast cancer patients using either standard cox model or stratified cox model. methods: the study was conducted on 15830 women diagnosed with breast cancer in british columbia, canada.  they were divided into eight groups according to patients’ ages and stage of disease either cox...

background: breast cancer is the most common cancer after lung cancer and the second cause of death. in this study we compared weibull and lognormal cure models with cox regression on the survival of breast cancer. study design: a cohort study. methods: the current study retrospective cohort study was conducted on 140 patients referred to ali ibn abitaleb hospital, rafsanjan southeastern iran f...

JOSEPH F. Ross, M.D., Edilor

JOSEPH F. Ross, M.D., Editor

JOSEPH F. Ross, M.D., Editor

JOSEPH F. Ross, M.D., Editor