| Gestation | R Documentation |
Birth weight, date, and gestational period collected as part of the Child Health and Development Studies in 1961 and 1962. Information about the baby's parents — age, education, height, weight, and whether the mother smoked is also recorded.
data(Gestation)
A data frame with 1236 observations on the following variables.
id identification number
pluralty 5 = single fetus
outcome 1 = live birth that survived at least 28 days
date birth date where 1096=January 1, 1961
gestation length of gestation (in days)
sex infant's sex (1=male, 2=female)
wt birth weight (in ounces)
parity total number of previous pregnancies (including fetal deaths
and still births)
race mother's race: 0-5=white 6=mex 7=black 8=asian 9=mixed
age mother's age in years at termination of pregnancy
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=Trade school, 7=HS unclear
ht mother's height in inches to the last completed inch
wt.1 mother's prepregnancy weight (in pounds)
drace father's race (a factor with levels equivalent to mother's race)
dage father's age (in years)
ded father'ed education (same coding as mother's education)
dht father's height in inches to the last completed inch
dwt father's weight (in pounds)
marital marital status: 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+
smoke does mother smoke? 0=never, 1=smokes now,
2=until current pregnancy, 3=once did, not now
time time since quitting smoking: 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
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
The data were presented by Nolan and Speed to address the question of whether there is a link between maternal smoking and the baby's health.
The book by Nolan and Speed describes the data in more detail and provides an Internet site for accessing them: http://www.stat.berkeley.edu/users/statlabs/
D Nolan and T Speed. Stat Labs: Mathematical Statistics Through Applications (2000), Springer-Verlag.
data(Gestation)