Hello,

Could you please advise as to whether or not the following analysis is suitable?

I would like to compare groups of monozygotic twins (MZ concordant vs. MZ 
control ; MZ discordant affected twin vs. unaffected twin) using qdec. This is 
not as straightforward as group comparisons usually are because I cannot make 
the assumption of all data being independent as twin pairs are, obviously, 
related to one another. 

To get around this issue I have started a qdec analysis and added a category 
'pair' in which twin pairs share a category as follows (qdec.table.dat), in 
order to indicate that they have shared genetic and environmental influence:

subject no
subjid  pair    diagnosis       age     gender
1       a       MZ_Discord_Well ...     ...
2       a       MZ_Discord_Ill          
3       b       MZ_Discord_Ill          
4       b       MZ_Discord_Well         
5       c       MZ_Discord_Well         
6       c       MZ_Discord_Ill          
7       h       MZ_Discord_Well         
8       h       MZ_Discord_Ill          
9       l       MZ_Discord_Well         
10      l       MZ_Discord_Ill          
11      m       MZ_Discord_Well         
12      m       MZ_Discord_Ill          
13      n       MZ_Discord_Well         
14      n       MZ_Discord_Ill          
15      p       MZ_Discord_Well         
16      p       MZ_Discord_Ill          
17      s       MZ_Discord_Well         
18      s       MZ_Discord_Ill          
19      t       MZ_Discord_Well         
20      t       MZ_Discord_Ill          

I would appreciate if you could suggest a more robust way around this.

Many thanks,

Rysia
_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer

Reply via email to