2.4. Statistical Analyses
weight gain
REGRESSION
Our local data (unpublished) indicated that very preterm infants with suboptimal growth velocity had an average weight gain of 13 g/kg/day (standard deviation (SD) = 7). A previous small study of 15 preterm infants showed a 7 g (SD = 4.4) increase in weight gain when hindmilk was fed [Descriptive statistics using mean, median, SD, and interquartile range (IQR) were used to describe the study population. A paired t test was used to compare average weight gain before and after hindmilk use. Linear regression analysis was used to assess the association between weight gain and milk content, and to adjust for potential confounding factors that included changes in measured milk protein, gestational age at birth, infant sex, exposure to low-dose postnatal dexamethasone to facilitate extubation (DART protocol) [