Detection of Risk Factor Interactions in Cerebral Palsy Using Statistical Methods

Background: The interaction of the risk factors is an important focus in medical study. The etiology of CP is multi-factorial and usually arises from a series of causal pathways. Objectives: The aim of this study was to compare four statistical methods to detect the interactions of risk factors of cerebral palsy (CP). Methods: In this cross-sectional study, 225 children aged 1 - 6 years were studied during 2008 and 2009 in Tehran, Iran. Penalized logistic regression (PLR), multifactor dimensionality reduction (MDR), logic regression (LR) and classification regression (CR) methods were used to detect interactions. Results: There was an interaction between the consanguinity factor and gender, asphyxia, preterm delivery, vaginal delivery, previous pregnancies, history of pregnancy, history of illness, sepsis, and small for gestational age (SGA). The methods used in this study were detect two-way (6 terms), three-way (11 terms) and four-way (2 terms) interaction terms. Of these interactions, asphyxia × consanguinity interaction was detected by MDR, LR, and CR methods. Conclusions: Our findings showed that the consanguinity factor had an interaction with most of the risk factors and especially consanguinity×asphyxia term was detected in allmethods. So this interaction term is very important for considering by clinicians.