title: Impact of one or two visits strategy on hypertension burden estimation in HYDY, a population-based cross-sectional study: implications for healthcare resource allocation decision making.
abstract: BACKGROUND
  The prevalence of hypertension in developing countries is coming closer to values found in developed countries. However, surveys usually rely on readings taken at a single visit, the option to implement the diagnosis on readings taken at multiple visits, being limited by costs.
  
  
  OBJECTIVE
  To estimate more accurately the magnitude and extent of the resource that should be allocated to the prevention of hypertension.
  
  
  METHODS
  Population-based cross-sectional survey with triplicate blood pressure (BP) readings taken on two separate home-visits.
  
  
  METHODS
  Rural and urban locations in three areas of Yemen (capital, inland and coast).
  
  
  METHODS
  A nationally representative sample of the Yemen population aged 15-69 years (5063 men and 5179 women), with an overall response rate of 92% in urban and 94% in rural locations.
  
  
  METHODS
  Hypertension diagnosed as systolic BP ≥140 mm Hg and/or diastolic BP ≥90 mm Hg and/or self-reported use of antihypertensive drugs.
  
  
  RESULTS
  Hypertension prevalence (age-standardised to the WHO world population 2001) based on fulfilling the same criteria on both visits (11.3%; 95% Cl 10.7% to 11.9%), was 35% lower than estimation based on the first visit (17.3%; 16.5% to 18.0%). Advanced age, blood glucose ≥7 mmol/l or proteinuria ≥1+ at dipstick test at visit one were significant predictors of confirmation at visit 2. The 959 participants found to be hypertensive at visit 1 or at visit 2 only and thus excluded from the final diagnosis had a rate of proteinuria (5.0%; 3.8% to 6.5%) comparable to rates of the general population (6.1%; 5.6% to 6.6%), and of subjects normotensive at both visits (5.6%; 5.1% to 6.2%). Only 1.9% of Yemen population classified at high or very high cardiovascular (CV) risk at visit 1 moved to average, low or moderate CV risk categories after two visits.
  
  
  CONCLUSIONS
  Hypertension prevalence based on readings obtained after two visits is 35% lower than estimation based on the first visit, subjects were excluded from final diagnosis belonging to low CV risk classes.
authors.affiliation: Department of Medical and Surgical Critical Care, University of Florence, Florence, Italy.
authors.forename: Pietro Amedeo
authors.initials: PA
authors.lastname: Modesti
authors.forename: Stefano
authors.initials: S
authors.lastname: Rapi
authors.forename: Mohamed
authors.initials: M
authors.lastname: Bamoshmoosh
authors.forename: Marzia
authors.initials: M
authors.lastname: Baldereschi
authors.forename: Luciano
authors.initials: L
authors.lastname: Massetti
authors.forename: Luigi
authors.initials: L
authors.lastname: Padeletti
authors.forename: Gian Franco
authors.initials: GF
authors.lastname: Gensini
authors.forename: Dong
authors.initials: D
authors.lastname: Zhao
authors.forename: Dawood
authors.initials: D
authors.lastname: Al-Hidabi
authors.forename: Husni
authors.initials: H
authors.lastname: Al Goshae