Here are the responses I received. Thanks a lot
for the advice :)
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one way, is to do it with bootstrap.
if you have the formula of the spearman coefficient then you write a code to
do that.
TH
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Specifying the right model, and using the appropriate covariance matrix
parameterization of the covariance matrix, a 95% CI can be obtained from
proc mixed in SAS. The calculation is based on a Wald-type test statistic,
using asymptotic normality of the ML or REML estimates.
Put the two variables underneath each other in one variable Y, and create a
factor (dummy) MEAS which is 1 for the first variable and 2 for the second.
Further, ID is a subject identification variable.
Fit following model:
proc mixed data=...;
class MEAS ID;
model Y=MEAS;
repeated MEAS / type=toeph subject=ID;
run;
I hope this helps.
Best regards,
Geert Verbeke
Biostatistical Centre
K.U.Leuven
Kapucijnenvoer 35
B-3000 Leuven
Belgium
Tel: +32 16 33 68 91
Tel (sec): +32 16 33 68 92
Fax: +32 16 33 70 15
Web: http://www.med.kuleuven.ac.be/biostat/
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It's much simpler than that!! The attached Excel spreadsheet
calculates a 95% CI for a correlation coefficient - assumed to be
Pearson, but still works the same for a Spearman except for very
small sample sizes.
Hope this helps.
..........................................
Robert G. Newcombe, PhD, CStat, Hon MFPHM
Reader in Medical Statistics
University of Wales College of Medicine
Heath Park
Cardiff CF14 4XN, UK.
Phone 029 2074 2329 or 2311
Fax 029 2074 3664
Email [log in to unmask]
Web:
http://www.uwcm.ac.uk/epidemiology_statistics/research/statistics/newc
ombe.h
tm
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