topic Re: Noninferiority hypothesis test from PROC FREQ using commonriskdiff in Statistical Procedures

Noninferiority hypothesis test from PROC FREQ using commonriskdiff

DGrint — Wed, 21 Sep 2022 14:05:20 GMT

Hello,

I have data in a series of stratified 2x2 tables, I want to calculate a p-value for a non-inferiority hypothesis test based on the common risk difference. There appears to be a way to do this using the riskdiff option, but not using the commonriskdiff option as far as I can see.

My proc freq tables statement looks like this:

tables site*trt*outcome / commonriskdiff(column=1 cl=(mh) printwts=(mh) test=(mh)) alpha=0.1;

The test=(mh) option is testing whether the common risk difference is different from 0, but in a non-inferioity setting we want to know if it is below a margin of non-inferiority, not 0.

If using the riskdiff option there are additional options (noninf margin=0.1 method=wald), which are used to define the margin of non-inferiority. But those options apply to the risk difference from each of the 2x2 tables, not the common risk difference.

Does anyone know who to test a non-inferiority hypothesis on a common risk difference?

Thanks,

Re: Noninferiority hypothesis test from PROC FREQ using commonriskdiff

Ksharp — Thu, 22 Sep 2022 11:44:01 GMT

That is totally two different method.
"commonriskdiff" is like CMH test for nx2x2 table(combine n riskdiff into one riskdiff).
But for Noninferiority test,you cann't do that ,Noninferiority is ONLY for 2x2 table.
Maybe @StatDave and @Rick_SAS knew the solution ?

Re: Noninferiority hypothesis test from PROC FREQ using commonriskdiff

DGrint — Thu, 22 Sep 2022 12:05:21 GMT

Exactly, I want a non-inferiority hypothesis p-value from a common risk difference (CMH). It appears there isn't a way to do this.

I've found a workaround, but it would be good if there were a simple option to calculate the non-inferiority test p-value.

Workaround: alter the level of significance (alpha) for the common risk difference until the limit of the CI matches the non-inferiorty margin. The p-value can then be calculated based on the alpha value.

Re: Noninferiority hypothesis test from PROC FREQ using commonriskdiff

Ksharp — Thu, 22 Sep 2022 12:15:00 GMT

Clever idea .
But that is still risk difference test , NOT non-inferiority test.

Re: Noninferiority hypothesis test from PROC FREQ using commonriskdiff

DGrint — Thu, 22 Sep 2022 12:20:54 GMT

I disagree.

Non-inferiority in this case is determined at the upper bound of the 95% CI for the common risk difference. If the CI for the risk difference is below a certain threshold (non-inferiority margin) then the experimental treatment is considtered non-inferior.

Risk difference and non-inferiority are not mutually exclusive. (Common) risk difference is the outcome, non-inferiority is hypothesis, rather than the standard scenario where this would be superiority (a comparison against the null of no difference).