CASESTOVARS
/ID=record_id
/INDEX=VisitDay
/GROUPBY=INDEX
/separator = "_"
/AUTOFIX =YES.

record_id  VisitDay   Site1  Site1nodule  Site2   Site2nodules
1001    Base        1   0       0   0
1001    VisitMo3    1   0       0   0
1001    VisitMo6    1   0       0   0
1002    Base        1   0       0   0
1002    VisitMo3    1   0       0   0
1002    VisitMo6    1   0       0   0
1003    Base            1   0       0   0
1003    VisitMo3    1   0       0   0
1003    VisitMo6    1   0       0   0

/autofix=no