title: What constitutes controlled hypertension? Patient based comparison of hypertension guidelines.
abstract: OBJECTIVE
  To investigate and quantify the extent to which variations in guidelines influence assessment of control of hypertension.
  
  
  METHODS
  Cross sectional study. Selected patients had hypertension assessed as controlled or uncontrolled with guidelines from New Zealand, Canada, the United States, Britain, and the World Health Organisation.
  
  
  METHODS
  18 general practices in Oxfordshire.
  
  
  METHODS
  876 patients with diagnosed hypertension and taking antihypertensive drugs.
  
  
  METHODS
  Proportion of patients with controlled hypertension according to each set of guidelines.
  
  
  RESULTS
  The proportion of patients with controlled hypertension varied from 17.5% to 84.6% with the different guidelines after adjustment for the sampling method. All five sets of guidelines agreed on the classification for 31% (277) of the patients. The New Zealand guidelines calculate an absolute risk of a cardiovascular event. When this was taken as the standard half of the patients with uncontrolled hypertension by the United States criteria would be treated unnecessarily and 31% of those classified as having controlled hypertension by the Canadian guidelines would be denied beneficial treatment.
  
  
  CONCLUSIONS
  Hypertension guidelines are inconsistent in their recommendations and need to make clear the absolute benefits and risks of treatment.
authors.affiliation: Department of Social Medicine, University of Bristol.
authors.forename: T P
authors.initials: TP
authors.lastname: Fahey
authors.forename: T J
authors.initials: TJ
authors.lastname: Peters
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D002170:Canada; D002318:Cardiovascular Diseases / Q000517:prevention & control; D003430:Cross-Sectional Studies; D006801:Humans; D006973:Hypertension / Q000628:therapy*; D008875:Middle Aged; D009520:New Zealand; D017410:Practice Guidelines as Topic; D012306:Risk; D006113:United Kingdom; D014481:United States
chemical_list: D000959:Antihypertensive Agents