Mothers and their babies data

Description

A collection of variables taken for each new mother in a Child and Health Development Study.

Usage

data(babies)

Format

A data frame with 1,236 observations on the following 23 variables.

Variables in data file

id

identification number

pluralty

5= single fetus

outcome

1= live birth that survived at least 28 days

date

birth date where 1096=January1,1961

gestation

length of gestation in days

sex

infant's sex 1=male 2=female 9=unknown

wt

birth weight in ounces (999 unknown)

parity

total number of previous pregnancies including fetal deaths and still births, 99=unknown

race

mother's race 0-5=white 6=mex 7=black 8=asian 9=mixed 99=unknown

age

mother's age in years at termination of pregnancy, 99=unknown

ed

mother's education 0= less than 8th grade, 1 = 8th -12th grade - did not graduate, 2= HS graduate–no other schooling , 3= HS+trade, 4=HS+some college 5= College graduate, 6&7 Trade school HS unclear, 9=unknown

ht

mother's height in inches to the last completed inch 99=unknown

wt1

mother prepregnancy wt in pounds, 999=unknown

drace

father's race, coding same as mother's race.

dage

father's age, coding same as mother's age.

ded

father's education, coding same as mother's education.

dht

father's height, coding same as for mother's height

dwt

father's weight coding same as for mother's weight

marital

1=married, 2= legally separated, 3= divorced, 4=widowed, 5=never married

inc

family yearly income in $2500 increments 0 = under 2500, 1=2500-4999, ..., 8= 12,500-14,999, 9=15000+, 98=unknown, 99=not asked

smoke

does mother smoke? 0=never, 1= smokes now, 2=until current pregnancy, 3=once did, not now, 9=unknown

time

If mother quit, how long ago? 0=never smoked, 1=still smokes, 2=during current preg, 3=within 1 yr, 4= 1 to 2 years ago, 5= 2 to 3 yr ago, 6= 3 to 4 yrs ago, 7=5 to 9yrs ago, 8=10+yrs ago, 9=quit and don't know, 98=unknown, 99=not asked

number

number of cigs smoked per day for past and current smokers 0=never, 1=1-4,2=5-9, 3=10-14, 4=15-19, 5=20-29, 6=30-39, 7=40-60, 8=60+, 9=smoke but don't know,98=unknown, 99=not asked

Source

This dataset is found from http://www.stat.berkeley.edu/users/statlabs/labs.html. It accompanies the excellent text Stat Labs: Mathematical Statistics through Applications Springer-Verlag (2001) by Deborah Nolan and Terry Speed.

Examples

data(babies)
plot(wt ~ factor(smoke), data=babies)
plot(wt1 ~ dwt, data=babies, subset=wt1 < 800 & dwt < 800)