title: Blood pressure variability of two ambulatory blood pressure monitors.
abstract: OBJECTIVE
  There are no data on the evaluation of blood pressure (BP) variability comparing two ambulatory blood pressure monitoring monitors worn at the same time. Hence, this study was carried out to compare variability of BP in healthy untreated adults using two ambulatory BP monitors worn at the same time over an 8-h period.
  
  
  METHODS
  An Accutorr device was used to measure office BP in the dominant and nondominant arms of 24 participants.Simultaneous 8-h BP and heart rate data were measured in 24 untreated adult volunteers by Mobil-O-Graph (worn for an additional 16 h after removing the Spacelabs monitor) and Spacelabs with both random (N=12) and nonrandom (N=12) assignment of each device to the dominant arm. Average real variability (ARV), SD, coefficient of variation, and variation independent of mean were calculated for systolic blood pressure, diastolic blood pressure, mean arterial pressure, and pulse pressure (PP).
  
  
  RESULTS
  Whether the Mobil-O-Graph was applied to the dominant or the nondominant arm, the ARV of mean systolic (P=0.003 nonrandomized; P=0.010 randomized) and PP (P=0.009 nonrandomized; P=0.005 randomized) remained significantly higher than the Spacelabs device, whereas the ARV of the mean arterial pressure was not significantly different. The average BP readings and ARVs for systolic blood pressure and PP obtained by the Mobil-O-Graph were considerably higher for the daytime than the night-time.
  
  
  CONCLUSIONS
  Given the emerging interest in the effect of BP variability on health outcomes, the accuracy of its measurement is important. Our study raises concerns about the accuracy of pooling international ambulatory blood pressure monitoring variability data using different devices.
authors.affiliation: aDepartment of Medicine, Renal, Electrolyte and Hypertension Division, University of Pennsylvania School of Medicine bDivision of Nephrology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.
authors.forename: Radhakrishna R
authors.initials: RR
authors.lastname: Kallem
authors.forename: Kevin E C
authors.initials: KE
authors.lastname: Meyers
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Cucchiara
authors.forename: Deirdre L
authors.initials: DL
authors.lastname: Sawinski
authors.forename: Raymond R
authors.initials: RR
authors.lastname: Townsend
mesh_terms: D000328:Adult; D062186:Arterial Pressure; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory / Q000295:instrumentation*; D015924:Blood Pressure Monitors; D015331:Cohort Studies; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D055815:Young Adult