The purposes were to compare the practice effect of stimulated whole saliva collection (SWSC) with unstimulated whole saliva collection (UWSC), and to investigate the validity of the tests as a criterion in the diagnosis of Sjogren's syndrome (SS), allowing for the practice effect.
SWSC (n = 34) or UWSC (n = 27) was performed 3 times on healthy volunteers to investigate practice effects; then the differences among the 3 measurements were analyzed. For evaluating the validity of the tests, UWSC and SWSC were performed alternately on 28 SS patients and 34 control subjects, all of whom had had a practice SWSC before the actual test; then the sensitivity and specificity of both tests as a criterion in the diagnosis of SS were calculated.
A practice effect was observed for SWSC, but not for UWSC. When an orientation measurement was performed before the actual SWSC, there was no statistically significant difference between the accuracy of SWSC and UWSC as a criterion in the diagnosis of SS.
If an orientation measurement is performed before the actual measurement, SWSC can be as valid a test for sialometric evaluation in the diagnosis of SS as UWSC.