Exercise: Analysis and power simulation for baseline/follow-up
measurements
================

## Shoulder pain and acupuncture

1.  Reanalyze the original data
    - Re-estimate the ANCOVA model for the Kleinhenz et al. (1999)
      [data](../data/kleinhenz.txt)
2.  Run a power simulation for a replication study
    1.  Draw plausible pre-CMS values
    2.  Specify the minimum relevant average treatment effect (ATE)
    3.  Set the remaining parameters to plausible values
    4.  What is the sample size required for the test to detect the
        effect with 80% power?
    5.  How robust is the power simulation when you repeat it with a new
        set of pre-CMS values? Try it!
    6.  Recover the parameters of the ANCOVA model

### References

<div id="refs" class="references csl-bib-body hanging-indent">

<div id="ref-KleinhenzStreitberger99" class="csl-entry">

Kleinhenz, J., K. Streitberger, J. Windeler, A. Güßbacher, G. Mavridis,
and E. Martin. 1999. “Randomised Clinical Trial Comparing the Effects of
Acupuncture and a Newly Designed Placebo Needle in Rotator Cuff
Tendinitis.” *Pain* 83 (2): 235–41.

</div>

</div>
