title: Clinical and Epidemiological Implications of 24-Hour Ambulatory Blood Pressure Monitoring for the Diagnosis of Hypertension in Kenyan Adults: A Population-Based Study.
abstract: The clinical and epidemiological implications of using ambulatory blood pressure monitoring (ABPM) for the diagnosis of hypertension have not been studied at a population level in sub-Saharan Africa. We examined the impact of ABPM use among Kenyan adults.
  
  
  
  We performed a nested case-control study of diagnostic accuracy. We selected an age-stratified random sample of 1248 adults from the list of residents of the Kilifi Health and Demographic Surveillance System in Kenya. All participants underwent a screening blood pressure (BP) measurement. All those with screening BP ≥140/90 mm Hg and a random subset of those with screening BP <140/90 mm Hg were invited to undergo ABPM. Based on the 2 tests, participants were categorized as sustained hypertensive, masked hypertensive, "white coat" hypertensive, or normotensive. Analyses were weighted by the probability of undergoing ABPM. Screening BP ≥140/90 mm Hg was present in 359 of 986 participants, translating to a crude population prevalence of 23.1% (95% CI 16.5-31.5%). Age standardized prevalence of screening BP ≥140/90 mm Hg was 26.5% (95% CI 19.3-35.6%). On ABPM, 186 of 415 participants were confirmed to be hypertensive, with crude prevalence of 15.6% (95% CI 9.4-23.1%) and age-standardized prevalence of 17.1% (95% CI 11.0-24.4%). Age-standardized prevalence of masked and white coat hypertension were 7.6% (95% CI 2.8-13.7%) and 3.8% (95% CI 1.7-6.1%), respectively. The sensitivity and specificity of screening BP measurements were 80% (95% CI 73-86%) and 84% (95% CI 79-88%), respectively. BP indices and validity measures showed strong age-related trends.
  
  
  
  Screening BP measurement significantly overestimated hypertension prevalence while failing to identify ≈50% of true hypertension diagnosed by ABPM. Our findings suggest significant clinical and epidemiological benefits of ABPM use for diagnosing hypertension in Kenyan adults.
authors.affiliation: KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya aetyang@kemri-wellcome.org.|London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Anthony O
authors.initials: AO
authors.lastname: Etyang
authors.affiliation: KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
authors.forename: Ben
authors.initials: B
authors.lastname: Warne
authors.affiliation: KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
authors.forename: Sailoki
authors.initials: S
authors.lastname: Kapesa
authors.affiliation: KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Munge
authors.affiliation: KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
authors.forename: Evasius
authors.initials: E
authors.lastname: Bauni
authors.affiliation: King's College, London, United Kingdom.
authors.forename: J Kennedy
authors.initials: JK
authors.lastname: Cruickshank
authors.affiliation: London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Liam
authors.initials: L
authors.lastname: Smeeth
authors.affiliation: KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.|London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: J Anthony G
authors.initials: JA
authors.lastname: Scott
mesh_terms: D017677:Age Distribution; D018660:Blood Pressure Monitoring, Ambulatory; D016022:Case-Control Studies; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000453:epidemiology; D007630:Kenya / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence
keywords: ambulatory blood pressure monitoring; diagnostic accuracy; hypertension; masked hypertension; sub‐Saharan Africa; white coat hypertension