title: Clinical characteristics and outcomes of myxedema coma: Analysis of a national inpatient database in Japan.
abstract: BACKGROUND
  Myxedema coma is a life-threatening and emergency presentation of hypothyroidism. However, the clinical features and outcomes of this condition have been poorly defined because of its rarity.
  
  
  METHODS
  We conducted a retrospective observational study of patients diagnosed with myxedema coma from July 2010 through March 2013 using a national inpatient database in Japan. We investigated characteristics, comorbidities, treatments, and in-hospital mortality of patients with myxedema coma.
  
  
  RESULTS
  We identified 149 patients diagnosed with myxedema coma out of approximately 19 million inpatients in the database. The mean (standard deviation) age was 77 (12) years, and two-thirds of the patients were female. The overall proportion of in-hospital mortality among cases was 29.5%. The number of patients was highest in the winter season. Patients treated with steroids, catecholamines, or mechanical ventilation showed higher in-hospital mortality than those without. Variations in type and dosage of thyroid hormone replacement were not associated with in-hospital mortality. The most common comorbidity was cardiovascular diseases (40.3%). The estimated incidence of myxedema coma was 1.08 per million people per year in Japan. Multivariable logistic regression analysis revealed that higher age and use of catecholamines (with or without steroids) were significantly associated with higher in-hospital mortality.
  
  
  CONCLUSIONS
  The present study identified the clinical characteristics and outcomes of patients with myxedema coma using a large-scale database. Myxedema coma mortality was independently associated with age and severe conditions requiring treatment with catecholamines.
authors.affiliation: Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan. Electronic address: onoyousuke1979@yahoo.co.jp.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Ono
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Ono
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Yasunaga
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Matsui
authors.affiliation: Department of Health Policy and Informatics, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fushimi
authors.affiliation: Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000453:epidemiology; D003128:Coma / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D015897:Comorbidity; D016208:Databases, Factual; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D007297:Inpatients / Q000706:statistics & numerical data*; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009230:Myxedema / Q000150:complications* / Q000175:diagnosis / Q000401:mortality*; D012189:Retrospective Studies
keywords: Hypothyroidism; Incidence; Mortality; Myxedema; Thyroid hormones