Statistical analysis
Univariate independent t-tests were used to test for significant
associations for normally distributed continuous variables and the
chi-squared and Fishers exact test were used for categorical variables.
Statistical hypotheses were tested using two-tailed 95% confidence
intervals (95% CI). Regression assumptions were met, and data were
analysed using multiple logistic regression modelling with maternal BMI,
maternal age, maternal education, deprivation level and smoking during
pregnancy as exposure variable, and GHQ depression >0 and
GHQ anxiety >6 as the dichotomous outcome variables.
Interaction analysis was carried out to determine if there were
differences in the regression associations between White British and
South Asian women i.e. associations between ethnicity and antenatal
depression and anxiety within each BMI category. The analyses were
performed using STATA version 16.