title: A Population-Based Analysis of Outcomes in Patients With a Primary Diagnosis of Hypertension in the Emergency Department.
abstract: Patients treated primarily for hypertension are common in the emergency department (ED). The outcomes of these patients who were given a primary ED diagnosis of hypertension have not been described at a population level. In this study, we describe the characteristics and outcomes of these patients, as well as changes over time.
  
  
  
  This retrospective cohort study used linked health databases from the province of Ontario, Canada, to assess ED visits made between April 1, 2002, and March 31, 2012, with a primary diagnosis of hypertension. We determined the annual number of visits, as well as the age- and sex-standardized rates. We examined visit disposition and assessed mortality outcomes and potential hypertensive complications at 7, 30, 90, and 365 days and at 2 years subsequent to the ED visit.
  
  
  
  There were 206,147 qualifying ED visits from 180 sites. Visits increased by 64% between 2002 and 2012, from 15,793 to 25,950 annual visits, respectively. The age- and sex-standardized rate increased from 170 per 100,000 persons to 228 per 100,000 persons during the same period, a 34% increase. Eight percent of visits ended in hospitalization, but this proportion decreased from 9.9% to 7.1% during the study period. Mortality was very low: less than 1% within 90 days, 2.5% within 1 year, and 4.1% within 2 years. Among subsequent hospitalizations for potential hypertensive complications, stroke was the most frequent admitting diagnosis, but the frequency was still less than 1% at 1 year. Together hospitalizations for stroke, heart failure, acute myocardial infarction, atrial fibrillation, renal failure, hypertensive encephalopathy, and dissection were less than 1% at 30 days.
  
  
  
  The number of visits made primarily for hypertension has increased significantly during the last decade. Although some of the increase is due to aging of the population, other forces are contributing to it as well. Subsequent mortality and complication rates are low and have declined. With current practice patterns, the feared complications of hypertension are extremely infrequent.
authors.affiliation: Division of Emergency Medicine, the Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Sameer
authors.initials: S
authors.lastname: Masood
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Austin
authors.affiliation: Division of Emergency Medicine, the Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada. Electronic address: clare.atzema@ices.on.ca.
authors.forename: Clare L
authors.initials: CL
authors.lastname: Atzema
mesh_terms: D000367:Age Factors; D000368:Aged; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012737:Sex Factors; D016896:Treatment Outcome