Computing Sample size for two controls per case study

[E. Bernardo]

Dear all,

 

Can we use GPower or SPSS SamplePower to compute the sample size for a two controls per case study?

The objective of the study is to investigate whether X profile has higher predisposition for a particular disease Y among case group compared to two healthy controls.  

Please suggest an alternative software in case SPSS SamplePower and GPower cannot handle.

Thank you.

Eins

[Maguin, Eugene]

Eins,

 

The Manova command can be used to compute power in situations where the manova model is appropriate. An article was written a number of years ago illustrating its use and there are periodic messages in the archives and, I think, the spss data management book that Raynald wrote several years ago.

 

Gene Maguin

 

 

From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Eins Bernardo
Sent: Friday, June 08, 2012 3:44 AM
To: [hidden email]
Subject: Computing Sample size for two controls per case study

 

Dear all,

 

Can we use GPower or SPSS SamplePower to compute the sample size for a two controls per case study?

The objective of the study is to investigate whether X profile has higher predisposition for a particular disease Y among case group compared to two healthy controls.  

 

Please suggest an alternative software in case SPSS SamplePower and GPower cannot handle.

 

Thank you.

 

Eins

[Bruce Weaver]

For a case-control study, I suppose you'll be using logistic regression.  You might find something useful here, in that case:

  http://www.pmean.com/09/SampleSizeLogistic.html

HTH.

Eins Bernardo wrote

Dear all,
 
Can we use GPower or SPSS SamplePower to
compute the sample size for a two controls per case study?
The
objective of the study is to investigate whether X profile has higher predisposition for a particular
disease Y among case group compared to two healthy controls.  

Please suggest an alternative software in
case SPSS SamplePower and GPower cannot handle.


Thank you.

Eins