 The list is not meant to be comprehensive and the impact of many of these variables could benefit from further research and discussion.In 2008 the Endocrine Society published diagnostic guidelines for Cushing’s syndrome, wherein they recommended midnight salivary cortisol testing on two consecutive days as one possible initial screening tool.A 2009 review concluded that late-night salivary cortisol testing is a suitable alternative to serum cortisol testing for diagnosing Cushing’s syndrome, reporting that both sensitivity and specificity exceeded ninety percent.