Found this article today on Dr. F's website and think it is very helpful. It has quite a bit of research data which is interesting and many of us have contributed to that data! Enjoy.
Title: High Prevalence of Normal Tests Assessing
Hypercortisolism in Subjects with Mild and Episodic
Cushing ’ s Syndrome Suggests that the Paradigm
for Diagnosis and Exclusion of Cushing ’ s Syndrome
Requires Multiple Testing