femSBMD {HRW}

Female spinal bone mineral densities

Description

The femSBMD data frame has longitudinal data on spinal bone mineral, density, age and ethnicity for female youths from a study on bone mineral acquisition.

Usage

data(femSBMD)

Format

This data frame contains the following columns:

idnum

identification number unique to each subject.

spnbmd

spinal bone mineral density in grams per square centimeter.

age

age of subject in years.

ethnicity

factor corresponding to the subject's ethnicity with levels Asian, Black, Hispanic and White.

black

indicator of the subject being black:
0 = subject is black
1 = subject is not black.

hispanic

indicator of the subject being Hispanic:
0 = subject is Hispanic
1 = subject is not Hispanic.

white

indicator of the subject being white:
0 = subject is white
1 = subject is not white.

Source

Bachrach, L.K., Hastie, T., Wang, M.-C., Narasimhan, B. and Marcus, R. (1999). Bone mineral acquisition in healthy Asian, Hispanic, Black, and Caucasian youth: a longitudinal study. Journal of Clinical Endocrinology and Metabolism, 84, 4702-4712.

Examples

library(HRW) ; data(femSBMD)
if (require("lattice"))
   print(xyplot(spnbmd ~ age|factor(ethnicity),groups = idnum,
                data = femSBMD,type = "b"))