title: A two-stage analysis of repeated measurements with dropouts and/or intermittent missing data.
abstract: This article is about a simple two-stage analysis that utilizes slope coefficients as the dependent variable for testing the significance of difference in mean rates of change in repeated measurement designs with missing data. The ANCOVA test on the doubly weighted slope coefficients provides power comparable to that of more complex maximum likelihood procedures when data are missing completely at random, requires fewer assumptions and is more generally applicable under realistic nonrandom dropout conditions, and most importantly can be readily understood and explained by those who actually do most controlled clinical research.
authors.affiliation: University of Texas Health Science Center, Department of Psychiatry and Behavioral Science, Houston, TX 77225, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Overall
authors.forename: Scott
authors.initials: S
authors.lastname: Tonidandel
mesh_terms: D000704:Analysis of Variance; D015982:Bias; D018849:Controlled Clinical Trials as Topic / Q000706:statistics & numerical data*; D003625:Data Collection / Q000706:statistics & numerical data; D006801:Humans; D010352:Patient Dropouts / Q000706:statistics & numerical data*; D011586:Psychology, Clinical / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D018401:Sample Size