Hello,

I need to calculate the z-scores from meta-GWAS summary stats. The association file has the following header

    rs_id   Allele1 Allele2 Freq1   Effect  StdErr  P.value

The 'effect' is the Beta coefficent. My understanding is

    z-score=Effect/StdErr

Is that correct? Also, are there any R packages that can do this?

Many thanks
You are correct. This can be very easily done with basic AWK or R:

AWK:

    awk '{if(NR == 1) print \$1; else if(NR > 1) print $0, \$5/\$6}' infile > outfile

R:

```
Infile<-read.table("infile.txt", head=T)
infile$z-score<-infile$Effect/infile$StdErr
head(Infile, 1)
```

    rs_id   Allele1 Allele2 Freq1   Effect  StdErr  P.value z-score