You can think of van Elteren's test as analogous to an analysis of variance with a blocking factor. One common use of the van Elteren test is with clinic as the stratification variable in a multicenter clinical study. van Elteren's test is used in lieu of randomized blocks ANOVA with clinics as blocks. In the case of a geographically distributed study we could use this test with country as a blocking factor
Here is how we could perform the test in SAS
data a;
input blocks treatmnt consump @@;
datalines;
1 1 236 1 2 255
2 1 183 2 2 179 2 2 193
3 1 115 3 1 128 3 2 132
4 1 61 4 1 70 4 1 79 4 2 67 4 2 84 4 2 88
;
proc freq;
tables blocks * treatmnt * consump / cmh2 scores=modridit noprint;
run;
