Medline ® Abstracts for References 6,7
of 'Blood pressure measurement in the diagnosis and management of hypertension in adults'
Use of automated office blood pressure measurement to reduce the white coat response.
Myers MG, Valdivieso M, Kiss A
J Hypertens. 2009 Feb;27(2):280-6.
OBJECTIVE: To examine the possibility of reducing the white coat response using an automated sphygmomanometer designed for office use, the BpTRU. Consecutive patients referred from physicians in the community to an ambulatory blood pressure (ABP) monitoring unit in an academic hospital were included in the study.
PARTICIPANTS AND METHODS: A total of 309 patients referred for diagnosis or management of hypertension were studied. Differences between mean awake ABP and BP readings taken by the patient's own physician using a manual sphygmomanometer or the automated BpTRU device with the patient resting alone in the ABP monitoring unit were compared.
RESULTS: BP recorded in the examining room using an automated device (132 +/- 19/75 +/- 12) was similar to the mean awake ABP (134 +/- 12/77 +/- 10) with both values being lower (P<0.001) than the BP recorded on a routine visit to the patient's own family physician (152 +/- 18/87 +/- 11). The coefficient of correlation between the systolic/diastolic ABP and the automated office BP (r = 0.62/0.72) was higher (P<0.001) than with the family physician's manual BP (r = 0.32/0.48). The prevalence of white coat hypertension in untreated patients (n = 146) was significantly (P<0.001) lower with automated office BP (16%) compared with the routine family physician BP (55%).
CONCLUSION: The white coat response associated with office BP measurements can be virtually eliminated by recording BP with the automated BpTRU device with patients resting alone in a quiet examining room.
Division of Cardiology, Schulich Heart Centre, Ontario, Canada. email@example.com
Conventional versus automated measurement of blood pressure in primary care patients with systolic hypertension: randomised parallel design controlled trial.
Myers MG, Godwin M, Dawes M, Kiss A, Tobe SW, Grant FC, Kaczorowski J
BMJ. 2011;342:d286. Epub 2011 Feb 7.
OBJECTIVE: To compare the quality and accuracy of manual office blood pressure and automated office blood pressure using the awake ambulatory blood pressure as a gold standard.
DESIGN: Multi-site cluster randomised controlled trial.
SETTING: Primary care practices in five cities in eastern Canada.
PARTICIPANTS: 555 patients with systolic hypertension and no serious comorbidities under the care of 88 primary care physicians in 67 practices in the community.
INTERVENTIONS: Practices were randomly allocated to either ongoing use of manual office blood pressure (control group) or automated office blood pressure (intervention group) using the BpTRU device. The last routine manual office blood pressure (mm Hg) was obtained from each patient's medical record before enrollment. Office blood pressure readings were compared before and after enrollment in the intervention and control groups; all readings were also compared with the awake ambulatory blood pressure.
MAIN OUTCOME MEASURE: Difference in systolic blood pressure between awake ambulatory blood pressure minus automated office blood pressure and awake ambulatory blood pressure minus manual office blood pressure.
RESULTS: Cluster randomisation allocated 31 practices (252 patients) to manual office blood pressure and 36 practices (303 patients) to automated office blood pressure measurement. The most recent routine manual office blood pressure (149.5 (SD 10.8)/81.4 (8.3)) was higher than automated office blood pressure (135.6 (17.3)/77.7 (10.9)) (P<0.001). In the control group, routine manual office blood pressure before enrollment (149.9 (10.7)/81.8 (8.5)) was reduced to 141.4 (14.6)/80.2 (9.5) after enrollment (P<0.001/P = 0.01), but the reduction in the intervention group from manual office to automated office blood pressure was significantly greater (P<0.001/P = 0.02). On the first study visit after enrollment, the estimated mean difference for the intervention group between the awake ambulatory systolic/diastolic blood pressure and automated office blood pressure (-2.3 (95% confidence interval -0.31 to -4.3)/-3.3 (-2.7 to -4.4)) was less (P = 0.006/P = 0.26) than the difference in the control group between the awake ambulatory blood pressure and the manual office blood pressure (-6.5 (-4.3 to -8.6)/-4.3 (-2.9 to -5.8)). Systolic/diastolic automated office blood pressure showed a stronger (P<0.001) within group correlation (r = 0.34/r = 0.56) with awake ambulatory blood pressure after enrollment compared with manual office blood pressure versus awake ambulatory blood pressure before enrollment (r = 0.10/r = 0.40); the mean difference in r was 0.24 (0.12 to 0.36)/0.16 (0.07 to 0.25)). The between group correlation comparing diastolic automated office blood pressure and awake ambulatory blood pressure (r = 0.56) was stronger (P<0.001) than that for manual office blood pressure versus awake ambulatory blood pressure (r = 0.30); the mean difference in r was 0.26 (0.09 to 0.41). Digit preference with readings ending in zero was substantially reduced by use of automated office blood pressure.
CONCLUSION: In compliant, otherwise healthy, primary care patients with systolic hypertension, introduction of automated office blood pressure into routine primary care significantly reduced the white coat response compared with the ongoing use of manual office blood pressure measurement. The quality and accuracy of automated office blood pressure in relation to the awake ambulatory blood pressure was also significantly better when compared with manual office blood pressure. Trial registration Clinical trials NCT 00214053.
Schulich Heart Centre, Department of Medicine, University of Toronto, Toronto, ON, Canada. firstname.lastname@example.org