Comparison of the dexamethasone suppression test and the cortisol suppression index

Among 50 inpatients, the sensitivity and specificity of the dexamethasone suppression test (DST) were 51.7% and 85.7%, respectively. For the cortisol suppression index they were 10.3% and 91% at 8:00 a.m. and 51.7% and 57.1% at 4:00 p.m. Thus, the cortisol suppression index does not appear to be an adequate substitute for the DST.