title: Risk factors promoting hypertensive crises: evidence from a longitudinal study.
abstract: BACKGROUND
  Current knowledge about risk factors promoting hypertensive crisis originates from retrospective data. Therefore, potential risk factors of hypertensive crisis were assessed in a prospective longitudinal study.
  
  
  METHODS
  Eighty-nine patients of the medical outpatient unit at the University Hospital of Bern (Bern, Switzerland) with previously diagnosed hypertension participated in this study. At baseline, 33 potential risk factors were assessed. All patients were followed-up for the outcome of hypertensive crisis. Cox regression models were used to detect relationships between risk factors and hypertensive crisis (defined as acute rise of systolic blood pressure (BP) > or =200 mm Hg and/or diastolic BP > or =120 mm Hg).
  
  
  RESULTS
  The mean duration of follow-up was 1.6 +/- 0.3 years (range 1.0-2.4 years). Four patients (4.5%) were lost to follow-up. Thirteen patients (15.3%) experienced hypertensive crisis during follow-up. Several potential risk factors were significantly associated with hypertensive crisis: female sex, higher grades of obesity, the presence of a hypertensive or coronary heart disease, the presence of a somatoform disorder, a higher number of antihypertensive drugs, and nonadherence to medication. As measured by the hazard ratio, nonadherence was the most important factor associated with hypertensive crisis (hazard ratio 5.88, 95% confidence interval 1.59-21.77, P < 0.01).
  
  
  CONCLUSIONS
  This study identified several potential risk factors of hypertensive crisis. Results of this study are consistent with the hypothesis that improvement of medical adherence in antihypertensive therapy would help to prevent hypertensive crises. However, larger studies are needed to assess potential confounding, other risk factors and the possibility of interaction between predictors.
authors.affiliation: Department of General Internal Medicine, Inselspital University of Bern Hospital, Bern, Switzerland.
authors.forename: Ardan M
authors.initials: AM
authors.lastname: Saguner
authors.forename: Stefan
authors.initials: S
authors.lastname: Dür
authors.forename: Martin
authors.initials: M
authors.lastname: Perrig
authors.forename: Uwe
authors.initials: U
authors.lastname: Schiemann
authors.forename: Andreas E
authors.initials: AE
authors.lastname: Stuck
authors.forename: Ulrich
authors.initials: U
authors.lastname: Bürgi
authors.forename: Paul
authors.initials: P
authors.lastname: Erne
authors.forename: Andreas W
authors.initials: AW
authors.lastname: Schoenenberger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006974:Hypertension, Malignant / Q000453:epidemiology*; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult