[R-meta] Back transformation of arcsine transformed data in meta-regression

Guido Schwarzer @c @end|ng |rom |mb|@un|-|re|burg@de
Thu Feb 6 09:09:04 CET 2020


The maximum value you can get for arcsine transformed proportions is 
1.571 (for a proportion of 100%) which you can see using the following R 
command: asin(sqrt(1))

Accordingly, the intercept 3.06 in your meta-regression is way of the 
mark due to extrapolating the effect of the continuous variable year. 
The intercept represents the effect at year 0 A.D.

I would suggest that you center the variable year around some value.

Best wishes, Guido

Dr. Guido Schwarzer
Institute of Medical Biometry and Statistics,
Faculty of Medicine and Medical Center - University of Freiburg

Postal address: Stefan-Meier-Str. 26, D-79104 Freiburg

Phone: +49/761/203-6668
Mail: sc using imbi.uni-freiburg.de
Homepage: http://www.imbi.uni-freiburg.de

ORCID iD: https://orcid.org/0000-0001-6214-9087
R-book: https://www.springer.com/gp/book/9783319214153

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