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

calciumLR Documentation

Data From The Calcium Supplements Study (Long Format)


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).

  • girl: patient identifier.

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

  • visit: visit index.

  • bmd: bone mineral density (mg/cm3).

  • time.obs: visit time (in years).

  • time.num: scheduled visit time (numeric variable, in years).

  • time.fac: scheduled visit time (factor variable).





LMMstar documentation built on Nov. 9, 2023, 1:06 a.m.