calciumL

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 long format (i.e. one line per measurement).
<ul>
<li><code>girl</code>: patient identifier.</li>
<li><code>grp</code>: treatment group: calcium supplement (coded <code>C</code>) or placebo (coded <code>P</code>).</li>
<li><code>visit</code>: visit index.</li>
<li><code>bmd</code>: bone mineral density (mg/cm3).</li>
<li><code>time.obs</code>: visit time (in years).</li>
<li><code>time.num</code>: scheduled visit time (numeric variable, in years).</li>
<li><code>time.fac</code>: scheduled visit time (factor variable).</li>
</ul>

datasets

Companion R package for the course "Statistical analysis of correlated and repeated measurements for health science researchers"
taught by the section of Biostatistics of the University of Copenhagen.
It implements linear mixed models where the model for the variance-covariance of the residuals is specified via patterns (compound symmetry, toeplitz, unstructured, ...).
Statistical inference for mean, variance, and correlation parameters is performed based on the observed information and a Satterthwaite approximation of the degrees of freedom.
Normalized residuals are provided to assess model misspecification.
Statistical inference can be performed for arbitrary linear or non-linear combination(s) of model coefficients.
Predictions can be computed conditional to covariates only or also to outcome values.

calciumL: Data From The Calcium Supplements Study (Long Format)

Description

Usage

Arguments

References