calciumW {LMMstar}

Data From The Calcium Supplements Study (Wide Format)

Description

Data from a randomized study including 112 girls at age 11 investigate the effect of a calcium supplement (n=55) vs. placebo (n=57) on bone mineral density over a 2 year follow-up. The clinical question is: does a calcium supplement help to increase bone gain in adolescent women? This dataset is in the wide format (i.e. one line per patient).

• girl: patient identifier

• grp: treatment group: calcium supplement (coded C) or placebo (coded P).

• obstime1: time after the start of the study at which the first visit took place (in years).

• obstime2: time after the start of the study at which the second visit took place (in years).

• obstime3: time after the start of the study at which the third visit took place (in years).

• obstime4: time after the start of the study at which the fourth visit took place (in years).

• obstime5: time after the start of the study at which the fifth visit took place (in years).

• bmd1: bone mineral density measured at the first visit (in mg/cm3).

• bmd2: bone mineral density measured at the second visit (in mg/cm3).

• bmd3: bone mineral density measured at the third visit (in mg/cm3).

• bmd4: bone mineral density measured at the fourth visit (in mg/cm3).

• bmd5: bone mineral density measured at the fifth visit (in mg/cm3).

Usage

data(calciumW)

References

Vonesh and Chinchilli 1997. Linear and Nonlinear models for the analysis of repeated measurement (Table 5.4.1 on page 228). New York: Marcel Dekker.