format
This data frame contains the following columns:
rl{
id: subject identifier: a numeric vector
d: case/control status: a numeric vector (1=case, 0=control)
age: a factor with levels
5-9
10-14
15-19
20-24
25-29
30-44
45+
sex: a factor with levels
male,
female
bcg: presence of vaccine scar, a factor with levels
no
yes
school: schooling, a factor with levels
none
1-5yrs
6-8yrs
sec/tert
house: housing, a factor with levels
brick
sunbrick
wattle
temp
}source
The study is described in more detail in Clayton and Hills, Statistical
Models in Epidemiology, Oxford University Press, Oxford:1993.