I have data from 3 studies. Study 202 and 203 got abundant sampling PK data (0, 0.5, 1, 2, 4, 6, 8, 12, 24 hr after dose), while Study206 had only sparse sampling (0, 1.5 hr) .
When I used only data from 202 and 203, the parameter shrinkage seems well. However, when adding data from 206, the shrinkage is large for study206 subjects.