Predictor variables entered into the model were parity, suction, chin contacts breast, and duration of naked body contact.
Beyond birth cohort, the covariates retained in the model were parity, family history of breast cancer, and self- versus proxy questionnaire completion.
Variables significant at univariate level but not in the full model were parity, public/private admission status, being born in Australia, type of birth, maternal BMI, and the use of epidural analgesia in labour.
Potential confounding variables included in the models were parity, maternal age, prepregnancy body mass index (BMI), smoking and alcohol consumption during pregnancy, maternal socioeconomic status (SES), sex of the child, parental behavioral problem scores during their own childhood, breast-feeding, birth year, household density, and gestational age at blood drawing.
Other variables that were tested, but not included in the models were parity (no child, 1 2, 3 4, 5 or more children), age at first parturition (no child, <=20, 21 29, 30 39, ⩾40 years of age) and family history of cancer in first-degree relatives.
Terms eliminated from the model in turn were parity (p=0.91), ethnicity (p=0.78), provider (p=0.73), infant provided with breast milk at time of call (p=0.69), how many times the helpline had been utilised (p=0.57), breastfeeding support provided by friends/family (p=0.53), first time caller (p=0.46), caller's age (p=0.56), child's age (p=0.38), helpline called (p=0.26) and time of call (p=0.18).
Variables included in the model were maternal age, race, parity, maternal hypertension or diabetes (gestational and pregestational) and smoking status.
Independent variables entered into the logistic models were age, parity, number of antenatal visits, marital status and level of education.
Predictor variables included as fixed effects in the models were breed, parity, week, herd and the interaction between week and herd.
The fixed effects in the model were: age, gestational age, ferritin and parity.
Phenotypes for calving traits were parity-specific daughter yield deviations estimated univariately via a sire model.
