TITLE:
Application of Survival Analysis in Studies of Human Ontogeny
AUTHORS:
Magdalena Kosińska, Anita Szwed
KEYWORDS:
Ontogenetic Events, Birth, Menarche, Menopause, Kaplan-Meier Method, Cox’s Proportional Hazard Model
JOURNAL NAME:
Applied Mathematics,
Vol.5 No.11,
June
20,
2014
ABSTRACT:
The main goal of
this work is to demonstrate the suitability of survival analysis for
ontogenetic studies. The research material includes retrospective data of the
age of the occurrence of ontogenetic events such as birth (N = 487), menarche
(N = 2016) and menopause (N = 3597). In order to study the time of occurrence
of ontogenetic events and to indicate the impact of environmental factors the
survival analysis was applied. First, the percentiles of functions established
for studied events were calculated. Next, the Kaplan-Meier survival curves were
derived. In the last step theinfluence of
environmental factors was established and the comparison of groups determined
based on the chosen factors was performed. The delivery time shows that 14% of
infants were bornpreterm. The risk of preterm delivery increases with
the severity of factors disrupting pregnancy (from none to coexisting maternal
and fetal risk factors) (; p ; p th and the 52nd years of life. The
time of menopause occurrence is significantly depended on both of considered
factors: the educational level and smoking cigarettes (, p