title: Prevalence of elevated hemoglobin A1c among patients admitted to the hospital without a diagnosis of diabetes.
abstract: BACKGROUND
  One in four hospitalized patients has diagnosed diabetes. The prevalence of unrecognized, or undiagnosed, diabetes among hospitalized patients is not well established.
  
  
  OBJECTIVE
  Our objective was to determine the prevalence of unrecognized probable diabetes in this patient population determined by elevated hemoglobin A1c (HbA1c) level.
  
  
  METHODS
  We conducted a prospective observational cohort trial with retrospective follow-up of patients with elevated HbA1c levels and no diagnosis of diabetes. HbA1c levels were obtained for all patients.
  
  
  METHODS
  The study was conducted at an acute care general hospital.
  
  
  METHODS
  Patients included 695 adult, nonobstetric patients admitted on 11 d in 2006.
  
  
  METHODS
  Outcome measures included rate of unrecognized probable diabetes, defined as admission HbA1c of more than 6.1% and no diagnosis of diabetes or treatment with antidiabetic medications before or during their admission and rate of unrecognized diabetes 1 yr after discharge.
  
  
  RESULTS
  Eighteen percent of hospitalized patients had elevated HbA1c levels without a diagnosis of diabetes. Random glucose levels poorly predicted elevated HbA1c levels (area under receiver operating characteristic curve, 0.60). Neither diagnosed diabetes nor HbA1c level was associated with length of stay or costs (P>0.1 for all comparisons). Only 15% of patients with elevated HbA1c levels who continued to receive care within the system studied had diabetes diagnosed in the year after the index admission.
  
  
  CONCLUSIONS
  Nearly one in five adult patients admitted to a large general hospital had unrecognized probable diabetes, based on elevated HbA1c levels. Random glucose levels during the hospital stay were poorly predictive of this condition. Few hospitalized patients with elevated HbA1c levels were diagnosed within the year after admission.
authors.affiliation: Massachusetts General Hospital Diabetes Center, Bulfinch 408, Massachusetts General Hospital, and Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, USA. dwexler@partners.org
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Wexler
authors.forename: David M
authors.initials: DM
authors.lastname: Nathan
authors.forename: Richard W
authors.initials: RW
authors.lastname: Grant
authors.forename: Susan
authors.initials: S
authors.lastname: Regan
authors.forename: Allison L
authors.initials: AL
authors.lastname: Van Leuvan
authors.forename: Enrico
authors.initials: E
authors.lastname: Cagliero
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D001900:Boston; D003920:Diabetes Mellitus / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006746:Hospital Bed Capacity, 500 and over / Q000706:statistics & numerical data; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012016:Reference Values
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin