title: Adequacy of a single visit for classification of hypertensive status in a Nigerian civil servant population.
abstract: BACKGROUND
  Concern has been expressed regarding the adequacy of classifying individuals as hypertensive based upon a single blood pressure determination and/or the average of readings taken at a single visit and the appropriateness of these determinations in cross-cultural comparisons of rates of hypertension.
  
  
  METHODS
  This analysis investigated the potential classification variability by comparing hypertensive status determined by 1) a single reading, 2) an average of the second and third determination at the first visit, and 3) an average of the second and third determinations obtained at each of three visits according to a standardized protocol. Kappa statistic, sensitivity and specificity were calculated to assess the agreement of hypertension classification for 804 subjects in the Health Survey in Nigerian Civil Servants, Benin City, 1992. Data were also compared to other published studies for variability in hypertension classification with repeated blood pressure determinations.
  
  
  RESULTS
  Good to excellent agreement was observed for the entire population between the single blood pressure determination, the average of the first visit, and the average of three visits. Sensitivity and specificity measures were also acceptable for the entire population. Further analysis by sex and staff status (a measure of socioeconomic status) found no apparent distinctions between the groups.
  
  
  CONCLUSIONS
  Contrasting the data with other published studies, conducted in both developed and developing countries, we note no greater variability in repeated blood pressure measurements, and conclude that the average of blood pressure determinations at a single visit in this working urban population is adequate for determining hypertensive status for comparisons with hypertension rates in Westernized populations.
authors.affiliation: Graduate School of Public Health, University of Pittsburgh, PA 15261.
authors.forename: N
authors.initials: N
authors.lastname: Markovic
authors.forename: I N
authors.initials: IN
authors.lastname: Olomu
authors.forename: C H
authors.initials: CH
authors.lastname: Bunker
authors.forename: S L
authors.initials: SL
authors.lastname: Huston
authors.forename: F A
authors.initials: FA
authors.lastname: Ukoli
authors.forename: L H
authors.initials: LH
authors.lastname: Kuller
mesh_terms: D000328:Adult; D001795:Blood Pressure Determination / Q000379:methods*; D002985:Clinical Protocols; D005260:Female; D006306:Health Surveys; D006801:Humans; D006973:Hypertension / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008403:Mass Screening / Q000379:methods; D009549:Nigeria / Q000453:epidemiology; D009790:Occupations; D011159:Population Surveillance / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012737:Sex Factors; D012959:Socioeconomic Factors; D014505:Urban Population