Sample size and power calculations in repeated measurement analysis

Controlled clinical trials in neuropsychopharmacology, as in numerous other clinical research domains, tend to employ a conventional parallel-groups design with repeated measurements. The hypothesis of primary interest in the relatively short-term, double-blind trials, concerns the difference betwee...

Full description

Saved in:
Bibliographic Details
Published in:Computer methods and programs in biomedicine 2001-02, Vol.64 (2), p.121-124
Main Authors: Ahn, Chul, Overall, John E, Tonidandel, Scott
Format: Article
Language:English
Subjects:
Biological and medical sciences
Computer simulation
Computerized, statistical medical data processing and models in biomedicine
Controlled Clinical Trials as Topic - statistics & numerical data
Dropouts
Humans
Medical sciences
Medical statistics
Numerical analysis
Power calculation
Repeated measures
Sample Size
Sample size estimate
Schizophrenia - drug therapy
Software
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Controlled clinical trials in neuropsychopharmacology, as in numerous other clinical research domains, tend to employ a conventional parallel-groups design with repeated measurements. The hypothesis of primary interest in the relatively short-term, double-blind trials, concerns the difference between patterns or magnitudes of change from baseline. A simple two-stage approach to the analysis of such data involves calculation of an index or coefficient of change in stage 1 and testing the significance of difference between group means on the derived measure of change in stage 2. This article has the aim of introducing formulas and a computer program for sample size and/or power calculations for such two-stage analyses involving each of three definitions of change, with or without baseline scores entered as a covariate, in the presence of homogeneous or heterogeneous (autoregressive) patterns of correlation among the repeated measurements. Empirical adjustments of sample size for the projected dropout rates are also provided in the computer program.
ISSN:0169-2607
1872-7565
DOI:10.1016/S0169-2607(00)00095-X