title: Corticotropin tests for hypothalamic-pituitary- adrenal insufficiency: a metaanalysis.
abstract: BACKGROUND
  The diagnostic value of tests for detecting hypothalamic-pituitary adrenal insufficiency (HPAI) is controversial.
  
  
  OBJECTIVE
  Our objective was to compare standard-dose and low-dose corticotropin tests for diagnosing HPAI.
  
  
  METHODS
  We searched the PubMed database from 1966-2006 for studies reporting diagnostic value of standard-dose or low-dose corticotropin tests, with patient-level data obtained from original investigators.
  
  
  METHODS
  Eligible studies had more than 10 patients. All subjects were evaluated because of suspicion for chronic HPAI, and patient-level data were available. We excluded studies with no accepted reference standard for HPAI (insulin hypoglycemia or metyrapone test) if test subjects were in the intensive care unit or if only normal healthy subjects were used as controls.
  
  
  METHODS
  We constructed receiver operator characteristic (ROC) curves using patient-level data from each study and then merged results to create summary ROC curves, adjusting for study size and cortisol assay method. Diagnostic value of tests was measured by calculating area under the ROC curve (AUC) and likelihood ratios.
  
  
  RESULTS
  Patient-level data from 13 of 23 studies (57%; 679 subjects) were included in the metaanalysis. The AUC were as follows: low-dose corticotropin test, 0.92 (95% confidence interval 0.89-0.94), and standard-dose corticotropin test, 0.79 (95% confidence interval 0.74-0.84). Among patients with paired data (seven studies, 254 subjects), diagnostic value of low-dose corticotropin test was superior to standard-dose test (AUC 0.94 and 0.85, respectively; P<0.001).
  
  
  CONCLUSIONS
  Low-dose corticotropin test was superior to standard-dose test for diagnosing chronic HPAI, although it has technical limitations.
authors.affiliation: John H. Stroger Jr. Hospital of Cook County and Rush Medical College, M.Sc., 1900 West Polk Street, Room 806, Chicago, Illinois 60612, USA. rasa_kazlauskaite@rush.edu
authors.forename: Rasa
authors.initials: R
authors.lastname: Kazlauskaite
authors.forename: Arthur T
authors.initials: AT
authors.lastname: Evans
authors.forename: Carmen V
authors.initials: CV
authors.lastname: Villabona
authors.forename: Tariq A M
authors.initials: TA
authors.lastname: Abdu
authors.forename: Bruno
authors.initials: B
authors.lastname: Ambrosi
authors.forename: A Brew
authors.initials: AB
authors.lastname: Atkinson
authors.forename: Cheung Hei
authors.initials: CH
authors.lastname: Choi
authors.forename: Richard N
authors.initials: RN
authors.lastname: Clayton
authors.forename: C Hamish
authors.initials: CH
authors.lastname: Courtney
authors.forename: E Nazli
authors.initials: EN
authors.lastname: Gonc
authors.forename: Mohamad
authors.initials: M
authors.lastname: Maghnie
authors.forename: Susan R
authors.initials: SR
authors.lastname: Rose
authors.forename: Steven G
authors.initials: SG
authors.lastname: Soule
authors.forename: Karen
authors.initials: K
authors.lastname: Tordjman
mesh_terms: D000307:Adrenal Gland Diseases / Q000175:diagnosis*; D000324:Adrenocorticotropic Hormone / Q000097:blood* / Q000378:metabolism; D000328:Adult; D002648:Child; D003366:Cosyntropin / Q000494:pharmacology; D005215:Fasting; D005938:Glucocorticoids / Q000009:adverse effects; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007027:Hypothalamic Diseases / Q000175:diagnosis*; D007030:Hypothalamo-Hypophyseal System; D010900:Pituitary Diseases / Q000175:diagnosis*; D012372:ROC Curve; D015203:Reproducibility of Results
chemical_list: D005938:Glucocorticoids; D003366:Cosyntropin; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone