title: Assessing the burden of diabetes mellitus in emergency departments in the United States: the National Hospital Ambulatory Medical Care Survey (NHAMCS).
abstract: OBJECTIVE
  To evaluate the performance of three alternative methods to identify diabetes in patients visiting Emergency Departments (EDs), and to describe the characteristics of patients with diabetes who are not identified when the alternative methods are used.
  
  
  METHODS
  We used data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) 2009 and 2010. We assessed the sensitivity and specificity of using providers' diagnoses and diabetes medications (both excluding and including biguanides) to identify diabetes compared to using the checkbox for diabetes as the gold standard. We examined the characteristics of patients whose diabetes was missed using multivariate Poisson regression models.
  
  
  RESULTS
  The checkbox identified 5,567 ED visits by adult patients with diabetes. Compared to the checkbox, the sensitivity was 12.5% for providers' diagnoses alone, 20.5% for providers' diagnoses and diabetes medications excluding biguanides, and 21.5% for providers' diagnoses and diabetes medications including biguanides. The specificity of all three of the alternative methods was >99%. Older patients were more likely to have diabetes not identified. Patients with self-payment, those who had glucose measured or received IV fluids in the ED, and those with more diagnosis codes and medications, were more likely to have diabetes identified.
  
  
  CONCLUSIONS
  NHAMCS's providers' diagnosis codes and medication lists do not identify the majority of patients with diabetes visiting EDs. The newly introduced checkbox is helpful in measuring ED resource utilization by patients with diabetes.
authors.affiliation: The University of Michigan, Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Ann Arbor, MI. Electronic address: kasao@uthsc.edu.
authors.forename: Keiko
authors.initials: K
authors.lastname: Asao
authors.affiliation: The University of Michigan, Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Ann Arbor, MI.
authors.forename: James
authors.initials: J
authors.lastname: Kaminski
authors.affiliation: The University of Michigan, Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Ann Arbor, MI.
authors.forename: Laura N
authors.initials: LN
authors.lastname: McEwen
authors.affiliation: The University of Michigan, Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Ann Arbor, MI; Eastern Michigan University, College of Health & Human Services, The Program of Health Administration, Ypsilanti, MI.
authors.forename: Xiejian
authors.initials: X
authors.lastname: Wu
authors.affiliation: The University of Michigan, Division of Pediatric Endocrinology, Child Health Evaluation and Research Unit, Ann Arbor, MI.
authors.forename: Joyce M
authors.initials: JM
authors.lastname: Lee
authors.affiliation: The University of Michigan, Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Ann Arbor, MI; The University of Michigan, Department of Epidemiology, Ann Arbor, MI.
authors.forename: William H
authors.initials: WH
authors.lastname: Herman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care / Q000191:economics / Q000706:statistics & numerical data; D003920:Diabetes Mellitus / Q000191:economics* / Q000628:therapy*; D004636:Emergency Service, Hospital / Q000191:economics* / Q000706:statistics & numerical data*; D005260:Female; D017048:Health Care Costs; D019538:Health Care Surveys; D006295:Health Resources / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: Diagnosis; Diagnosis code; Emergency room; Sensitivity; The National Hospital Ambulatory Medical Care Survey (NHAMCS)