Statistical analysis
The agreement of case ascertainment between the
computerized database of the Statistical Unit and
medical record review was verified before going on the
analysis. All statistical analyses were performed using Statistical Package for Social Science version 16
statistical software. Continuous data were presented
descriptively by mean if data were normally distributed or
median if data were not normally distributed. The
preterm delivery cases were classified according to the
patho-physiological groups. (i.e.,premature rupture of
membranes [PPROM] and medically indicated preterm
delivery) .27,32 Odds ratio with 95% confidence interval of
factors associated with the occurrence of preterm
delivery were calculated using univariable (crude odds
ratio-COR) and multivariable analysis (logistic
regression)(adjusted odds ratio-AOR). Statistical
significance was considered achieved when the p-value
was less than 0.05. "