Cortisol levels are predictors of severity and outcome in CAP to a similar extent to the PSI, and are better than routinely measured laboratory parameters. In CAP, the prognostic accuracy of FC is not superior to TC. Clinical trial registered with www.controlled-trials.com (ISRCTN04176397).

The more pronounced increase in FC seen during stress as compared with the ACTH test suggests that this test does not adequately anticipate the FC levels needed during severe stress.