SAMPLE SIZE for a cross over AB/BA with binary variable

COMPAREMISSING — Tue, 19 Jul 2016 09:46:22 GMT

I have a cross over AB/BA with binary variable. I have 16 subjects who take 2 treatments in 2 periods. the 16 are diveded in 2 groups which follow 2 diffrerent sequences:AB and BA

I have to analyze it as:

PROC GENMOD DATA= sample DESCENDING;
CLASS TREATMENT PERIOD SUBID;
MODEL Y = TREATMENT PERIOD /LINK=LOGIT DIST=BIN;
REPEATED SUBJECT=SUBID ;
RUN;

how i can calulate the power?

Thanks a lot,

Barbara

Re: SAMPLE SIZE for a cross over AB/BA with binary variable

SteveDenham — Wed, 20 Jul 2016 17:30:14 GMT

Simulation is your best bet. However, with transformations (logit) you might be able to use PROC GLMPOWER. You will need good estimates of the correlation over time to get an accurate estimate. If you have SAS/STAT14.1, look at Example 48.3 Repeated Measures ANOVA as a starting place.

Steve Denham

topic SAMPLE SIZE for a cross over AB/BA with binary variable in Statistical Procedures

SAMPLE SIZE for a cross over AB/BA with binary variable

Re: SAMPLE SIZE for a cross over AB/BA with binary variable