Hi everyone

I have the following problem: My dataframe has 3 variables: ID, Year and 
and an outcome variable. The dataframe contains repeated measurements 
because the subjects filled out a questionnaire every year. The time span 
covers 2 years.

Now I want to check if there is a significant change in the outcome over 
the 2 years with a paired wilcox.test. The problem: Not every subject 
completed both questionnaires. Thus, some subjects have the outcome only 
for year1 and others only for year2.

If I try wilcox.test(Outcome~Year, paired=T), I receive an error "not the 
same length".

Is there a fast method to remove those subjects with missing outcomes?

Thanks for any help.

Regards,
Denis Aydin

_____________________________________________

Denis Aydin, MSc

Swiss Tropical and Public Health Institute
Socinstrasse 57, P.O. Box
4002 Basel, Switzerland

T +41 (0)61 270 22 04
F +41 (0)61 270 22 25
@ denis.aydin@unibas.ch

_____________________________________________

Postal address:

Denis Aydin, MSc
Swiss Tropical and Public Health Institute
Socinstrasse 57, P.O. Box
4002 Basel, Switzerland

Visitors address:

Kanonengasse 27
4051 Basel, Switzerland

_____________________________________________

Swiss TPH website: www.swisstph.ch
 
Former ISPM: www.ispm-unibas.ch
Former STI: www.sti.ch



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