MIXTURE AND NON-MIXTURE CURED MODELS IN SURVIVAL ANALYSIS OF LEUKEMIA PATIENTS: A COHORT STUDY

The present study analyzed the factors affecting the survival time of patients with leukemia from diagnosis to death, taking into account the cure rate. The aim of the present study was to apply two models of mixed and unmixed healing in the data of patients with leukemia who received bone marrow transplantation.

In this descriptive-analytical (Cohort) research, the data of 351 patients who were referred to Taleghani Hospital in Tehran affiliated to Shahid Beheshti University of Medical Sciences and received bone marrow transplantation due to leukemia were examined. Patients received bone marrow transplantation between 2007 and 2014 and were followed up until 2016. In this study, the cured models of Bernoulli-Weibull blended (taking into account the Bernoulli distribution for latent variables and the Weibull distribution for survival time) and the Poisson -Weibull blended cured model (considering the Poisson distribution for latent time variables for hiding and distribution and distribution for survival time) were fitted to the data.

In this study, 351 patients, 197 males (56.1%) and 154 females (43.9%), were studied in which 67 patients (19.1%) died. Among the significant variables of recurrence after transplantation, recurrence before transplantation, hemoglobin, type of transplant, age, body mass, blood type and type of diagnosis, variables age (p=0.01), recurrence after transplantation (0.03) and type of transplant (p=0.03) are among the variables affecting the survival time of leukemia patients. In the mixture cured model of Bernoulli-Weibull and the variables of age (p=0.004), recurrence after transplantation (p=0.013) and type of diagnosis (p<0.008) were variables affecting the survival time of leukemia patients in the non-mixture cured model Poisson -Weibull.

Patients with autologous bone marrow transplantation under the age of 30 have a better chance of survival, and also the non-mixture cured model has a better outcome than the mixture cured model.