Risk factors associated with low infant birth weight
birthwtA data frame with 189 rows and 19 variables. The first 10 columns are included in the dataset of the same name in the MASS package. The remaining 9 columns are defined in Claeskens and Hjort (2008), and are included in this dataset for convenience.
indicator of birth weight less than 2.5 kg
mother's age in years
mother's weight in pounds at last menstrual period
mother's race (<U+2018>1<U+2019> = white, <U+2018>2<U+2019> = black, <U+2018>3<U+2019> = other)
smoking status during pregnancy
number of previous premature labours
history of hypertension
presence of uterine irritability
number of physician visits during the first trimester
birth weight in grams
Binary indicator for both smoking and uterine irritation
Interaction between age and binary (0/1) smoking status, that is, age for smokers and zero for non-smokers.
Intercept term (all 1)
Binary indicator for race "other"
Binary indicator for race "black"
Binary indicator for ftv, number of physician visits during the first trimester, 2 or more
Binary indicator for ftv 1
Binary indicator for ptl, number of previous premature labours, 1 or more
Weight measured in kg, as used in Claeskens and Hjort. Note lwt, as used in MASS, is in pounds.
Claeskens, G., & Hjort, N. L. (2008). Model selection and model averaging (Vol. 330). Cambridge: Cambridge University Press.