title: Effect of placebo on ambulatory blood pressure monitoring in children.
abstract: BACKGROUND
  Ambulatory blood pressure monitoring (ABPM) has been proposed as a useful tool for more accurately diagnosing hypertension (HTN) and evaluating blood pressure (BP) response in pediatric anti-hypertensive trials. ABPM captures multiple BP measurements during routine daily activities and is thus an excellent method for identifying white-coat HTN. Additionally, ABPM measurements in adults do not demonstrate the placebo effect commonly seen with casual BP measurements, although this has yet to be evaluated in children. Therefore,, the aim of this study was to assess the effect of placebo on ABPM measurements in children.
  
  
  METHODS
  A total of 141 children aged 5-16 years with elevated BP were randomized into a multi-center, single-blind, cross-over trial. Subjects received a placebo pill prior to wearing a 24-h ABPM device at one of two visits separated by 1-2 weeks. Study procedures were otherwise identical at both visits.
  
  
  RESULTS
  Mean systolic and diastolic BP for all measured time periods were similar between visits, as was the number of children diagnosed with HTN at each visit.
  
  
  CONCLUSIONS
  Having confirmed HTN at baseline did not affect the impact of placebo on mean BP. If confirmed, this lack of placebo effect on ABPM measurements may allow for the design of direct comparison pediatric anti-hypertensive trials without a placebo arm.
authors.affiliation: Division of Pediatric Nephrology, Department of Pediatrics, University of Arkansas for Medical Sciences & Arkansas Children's Hospital, Little Rock, AR, USA. redwinekarenm@uams.edu
authors.forename: Karen
authors.initials: K
authors.lastname: Redwine
authors.forename: Lee
authors.initials: L
authors.lastname: Howard
authors.forename: Pippa
authors.initials: P
authors.lastname: Simpson
authors.forename: Shun-Hwa
authors.initials: SH
authors.lastname: Li
authors.forename: Ke
authors.initials: K
authors.lastname: Yan
authors.forename: Laura
authors.initials: L
authors.lastname: James
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Blumer
authors.forename: Janice
authors.initials: J
authors.lastname: Sullivan
authors.forename: Robert
authors.initials: R
authors.lastname: Ward
authors.forename: Thomas
authors.initials: T
authors.lastname: Wells
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D002648:Child; D002675:Child, Preschool; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D009819:Office Visits; D015990:Placebo Effect; D011237:Predictive Value of Tests; D016037:Single-Blind Method; D014481:United States