If randomization was used to create the groups of analytic units for comparison of outcome then consider the following:
Guanghan F. Liu∗,†, Kaifeng Lu, Robin Mogg, Madhuja Mallick and Devan V. Mehrotra: Should baseline be a covariate or dependent variable in analyses of
change from baseline in clinical trials? Statist. Med. 2009; 28:2509–2530
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Brent Blumenstein
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