Factors Associated with Survival of Patients with Leukemia Using Penalized Splines and Comparing That with the Cox Proportional Hazards Model

Leukemia is one of the most common and deadly diseases which is an important health problem. The aim of this study was to evaluate the survival of patients with acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML) using the penalized splines model and comparing that with the Cox proportional hazards model.

This is a longitudinal survival research that used data from patients referred to Tehran Imam Khomeini Hospital between 2011 and 2014 and followed until 2016. Patients' information was collected through census, using a researcher-made checklist based on their files. Furthermore, the patients' latest status was obtained via phone calls. All medical records of the patients referred to Amir Al-Momenin hospital in Maragheh and diagnosed with prostate hyperplasia and underwent prostatectomy between 2014 and 2019 were examined taking a census. Kaplan-Meier nonparametric method was used to assess the 5-year survival rate, and Cox's semiparametric model was used to determine the risk factors in subgroups. Then, the penalized spline regression model was fitted using the R software version 4.2.2.

The average age of patients was 36.29±16.01 and 36.7% of the patients were men. Half of the patients died, and 12.7% experienced recurrence. Acute lymphoblastic leukemia affected 34.7% of the patients, whereas acute myeloblastic leukemia affected 63.3%. The 5-year-survival rates for patients with ALL and AML were 18% and 29%, respectively. Age, white blood cell count, platelet count, and hemoglobin levels were found to be significantly associated with patients' survival (P<0.05).

Leukemia is seen at young ages in Iran, so, early detection and treatment of the disease can play a critical role in improving the survival of patients.