title: A multicenter evaluation of the A&D TM-2420 ambulatory blood pressure recorder.
abstract: The A&D TM-2420 (A&D Engineering, Milpitas, CA) is an automatic, portable, noninvasive blood pressure (BP) recorder which uses a dual microphone system for the detection of Korotkoff sounds. Its accuracy and clinical performance were assessed in a multicenter study that also addressed issues such as observer agreement and the effects of age, arm circumference, heart rate, posture, and blood pressure level on the observer-device differences. We compared 906 simultaneous, same-arm BP measurements in 151 subjects using the TM-2420 versus two skilled clinicians per site using a teaching stethoscope. The agreement between the TM-2420 and mercury column determinations were within 10 mm Hg for 86 to 91% of systolic readings and 91 to 94% of diastolic readings, depending on the posture; a level of agreement which would receive a 'B+' grade from the recent British Hypertension Society guidelines. The limits of agreement (2 standard deviations about the mean difference) for systolic BP between observers and the TM-2420 tended to be greater for the standing position (-20 to 15 mm Hg) compared to supine (-14 to 12 mm Hg) and seated (-13 to 8 mm Hg) positions. Limits of agreement between the observers and device were not dependent upon age, heart rate, arm size, or blood pressure level. Twenty-four-hour blood pressure monitoring in two of the four centers demonstrated an error code rate of 3.4%, excluding 'retries' that are one of the device's features. These data demonstrate an acceptable level of accuracy and performance of the sixth generation of the TM-2420 for use in clinical practice and research.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Division of Cardiology, University of Connecticut Health Center, Farmington 06030.
authors.forename: W B
authors.initials: WB
authors.lastname: White
authors.forename: T G
authors.initials: TG
authors.lastname: Pickering
authors.forename: J
authors.initials: J
authors.lastname: Morganroth
authors.forename: G D
authors.initials: GD
authors.lastname: James
authors.forename: E J
authors.initials: EJ
authors.lastname: McCabe
authors.forename: O
authors.initials: O
authors.lastname: Moucha
authors.forename: H
authors.initials: H
authors.lastname: Hunter
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D000553:Ambulatory Care / Q000379:methods / Q000592:standards*; D001132:Arm / Q000033:anatomy & histology; D001794:Blood Pressure / Q000502:physiology; D001795:Blood Pressure Determination / Q000379:methods; D015924:Blood Pressure Monitors / Q000592:standards*; D002940:Circadian Rhythm / Q000502:physiology; D005069:Evaluation Studies as Topic; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008875:Middle Aged