You are here: CTSPedia>CTSpedia Web>StatisticalTools>SasTools>PowESDNested (29 Mar 2010, RuiChen)EditAttach
-- RuiChen - 29 Mar 2010

MacroHeaderForm edit

Macro Name %ESDPowNested
Description This program computes detectable Effect Size for a pre-specified power or for a pre-specified effect size between two treatment conditions for group study within a longitudinal setting, assuming equal group size.

Effect size is defined as in Cohen (1988):ef = (mu1 - mu2)/ sqrt[(var1 + var2)/2]
Macro Parameters alpha = significant level
Power = detectable power (if this value is specified, the macro is used to calculate the effect size difference for a given power. otherwise, leave it blank.)
EFD = detectable effect size difference (if this value is specified, the macro is used to calculate the power for a given effect size difference. otherwise, leave it blank.)
Test = 1 or 2, where 1 = one-sided test; 2 = two-sided test

Parameters for groups:
ICC = intraclass correlation;
group = group size;
Ngrp1 = sample size for group 1 (= sample size for group 2);

Parameters for longitudinal study design:
Nrep = number of repeated measures in f/u assessments;
CorrCoef = correlation coefficient;
MissRate = missing rate over entire study period;
startp = 0.01; change this value if error appears in the log file; file;
Programmer Rui Chen
Revision March 29, 2010
Disclaimer This SAS macro is developed by Xin Tu and Rui Chen in the Department of Biostatistics and Computational Biology at the University of Rochester under the auspice of the CTSI BREAD with the intent to facilitate data analyses and reporting in clinical and related research. It is copyrighted by Dr. Tu, March, 2010 and distributed for free public access.
Example(s) SampleRun.sas: An example.
Special Features

Called Macros

Notes

See Also %EFDPowlongitud
Edit | Attach | Print version | History: r1 | Backlinks | Raw View | Raw edit | More topic actions
Topic revision: r1 - 29 Mar 2010 - 14:50:40 - RuiChen
 
Copyright &© by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding CTSPedia? Send feedback