title: The shortened combined clonidine and arginine test for growth hormone deficiency is practical and specific: a diagnostic accuracy study.
abstract: BACKGROUND
  The growth hormone (GH) stimulation protocols for clonidine and arginine tests are non-standardized and can be lengthy. We examined the specificity of both tests using a shorter duration of timed samples: 90 min for clonidine and 60 min for arginine.
  
  
  METHODS
  We retrospectively studied all children who had GH stimulation with clonidine and arginine to test for GH deficiency (GHD). We compared the diagnostic accuracy of both reference and new shortened test (index).
  
  
  RESULTS
  We reviewed 243 charts (11.4±4.1 years old; 74.5% males). The combined reference test was performed on 159 children, 29 (18.3%) tested positive for GHD on the combined index test, Kappa 0.98, false positive rate 1 (0.8%), specificity 0.99, 95th CI (0.96-1), and p=1.0. The specificity of both the clonidine and arginine single index tests was 0.98%.
  
  
  CONCLUSIONS
  The shortened clonidine and arginine stimulation index tests have good specificity. This is a viable option for testing children for GHD.
authors.forename: Reem
authors.initials: R
authors.lastname: Al Khalifah
authors.forename: Lina
authors.initials: L
authors.lastname: Moisan
authors.forename: Helen
authors.initials: H
authors.lastname: Bui
mesh_terms: D001120:Arginine; D015415:Biomarkers / Q000097:blood*; D002648:Child; D003000:Clonidine; D003430:Cross-Sectional Studies; D003940:Diagnostic Techniques, Endocrine / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006130:Growth Disorders / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; D001120:Arginine; D003000:Clonidine