birthwt {fic}

Risk factors associated with low infant birth weight

Description

Risk factors associated with low infant birth weight

Usage

birthwt

Format

A 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.

low

indicator of birth weight less than 2.5 kg

age

mother's age in years

lwt

mother's weight in pounds at last menstrual period

race

mother's race (‘1’ = white, ‘2’ = black, ‘3’ = other)

smoke

smoking status during pregnancy

ptl

number of previous premature labours

ht

history of hypertension

ui

presence of uterine irritability

ftv

number of physician visits during the first trimester

bwt

birth weight in grams

smokeui

Binary indicator for both smoking and uterine irritation

smokeage

Interaction between age and binary (0/1) smoking status, that is, age for smokers and zero for non-smokers.

intercpt

Intercept term (all 1)

raceother

Binary indicator for race "other"

raceblack

Binary indicator for race "black"

ftv2p

Binary indicator for ftv, number of physician visits during the first trimester, 2 or more

ftv1

Binary indicator for ftv 1

ptd

Binary indicator for ptl, number of previous premature labours, 1 or more

lwtkg

Weight measured in kg, as used in Claeskens and Hjort. Note lwt, as used in MASS, is in pounds.

Source

MASS package (Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer); originally from Hosmer, D.W. and Lemeshow, S. (1989) Applied Logistic Regression. New York: Wiley

References

Claeskens, G., & Hjort, N. L. (2008). Model selection and model averaging (Vol. 330). Cambridge: Cambridge University Press.