Daniel,

If you have PROC IML licensed, then I can provide you with my own macro for performing a paired data permutation test. Let me know if you would like to receive it and I will send it as an attachment directly to you.

Dale

--- Daniel <daniel.biostatistics@GMAIL.COM> wrote:

> Good morning all, > > I would like to apply the methods of Gail et al. ("On Design > Considerations and Randomization-Based Inference for Community > Intervention Trials"; Stat Med 15; 1069-1092) to my data which come > from a cross-sectional group-randomized trial with matched pairs. > > Regarding the design, we had 10 pairs of clinics that were matched > and > for each clinic I computed the difference (W_i) of the log odds of my > outcome (dichotomous, measured at the patient level) at times 1 > (post- > intervention) and 0 (baseline). For each pair, I then computed the > difference W_1 - W_0, where W_1 corresponds to the experimental > treatment group's difference, and W_0 corresponds to the control > group's difference. I therefore have 10 differences, of which I then > computed the mean (U). > > I would like to do a permutation test. More specifically, I would > like > to compute, for each of the 2**10 possible permutational scenarios, > the mean of those differences, and then determine the proportion of > those means that are as extreme or more than my original data's U. > > My question is: is there a way to do this in SAS, using a procedure's > option (as opposed to programming the algorithm, which I'll be happy > to do if there are no built-in functions)? Because there are only > 1024 > scenarios, I would like to enumerate all of them as opposed to > selecting just a random sample. > > Thank you in advance for your input, > > Daniel >

--------------------------------------- Dale McLerran Fred Hutchinson Cancer Research Center mailto: dmclerra@NO_SPAMfhcrc.org Ph: (206) 667-2926 Fax: (206) 667-5977 ---------------------------------------

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