You can use the SAMPLINGUNIT | CLUSTER statement in PROC SURVEYSELECT to select patient IDs instead of observations. For example, add samplingunit patientID; proc surveyselect data = data_set method = SRS sampsize = 100 seed = 12345 out = sample_ds; id _all_; strata sart_id; samplingunit patientID; run;   ... View more

Usage Note: Testing the equality of two or more proportions from independent samples  ... View more

The value that is labeled "Zelen's Exact Test (P)" is the test statistic, and the value that is labeled "Exact Pr <=P" is the p-value for the test.    From the documentation (section "Zelen's Exact Test for Equal Odds Ratios"):   "The test statistic [for Zelen's test] is the probability of the observed table conditional on the fixed margins, which is a product of hypergeometric probabilities.   The p-value for Zelen’s test is the sum of all table probabilities that are less than or equal to the observed table probability, where the sum is computed over all tables in the reference set determined by the fixed margins and the observed sum of cell (1,1) frequencies. This test is similar to Fisher’s exact test for two-way tables.   For more information, see Zelen (1971); Hirji (2006); Agresti (1992)."   ... View more