To What Extent Can We Trust Home Blood Pressure Measurement? A Randomized, Controlled Trial

Abstract

Increasingly, patients measure and record their home blood pressure. However, the accuracy with which they report their readings to their physicians is largely unknown. The authors assessed the accuracy and quality of self-reported home blood pressure values in an ambulatory managed care population. Forty-eight hypertensive outpatients were randomly allocated to either receive information about the storage capabilities of a home blood pressure measuring device or not to receive such information. All patients were asked to record the measurement results in a logbook twice daily over a 7-day period. The main outcome measure was the difference in the number of fictional or manipulated reports per group and the difference in missing values. The combined parameter manipulated or fictional registrations occurred significantly less frequently in the informed group than in the noninformed group. (10/728 vs. 29/616; relative risk, 0.292; 95% confidence interval, 0.15-0.57; Pearson chi squared=13.15; p<0.0001). Informed patients had fewer missing registrations than the noninformed (13/728 vs. 41/616 measurements; relative risk, 0.27; 95% confidence interval, 0.15-0.47; Pearson chi squared =20.5; p<0.0001). The mean of the fictional data did not differ systematically from the mean of the correctly reported individual blood pressure values. There was no trend to over- or underestimate blood pressure values in the noninformed group. With this study design, it was possible to identify manipulation of home blood pressure values for the first time. Accuracy and interpretation of home blood pressure measurement may be increased by using devices with a memory function.

Determinants of Negative White-Coat Effect In Treated Hypertensive Patients: The Jichi Morning Hypertension Research (J-MORE) Study

“…We asked the physicians to use validated BP monitors, but the accuracy with which their patients recorded their readings is largely unknown. 22 We chose the 3-day, twice-daily measurement regime according to established guidelines. 8 However, a recent report recommended more measurements.…”

When Tight Blood Pressure Control Is Not for Everyone: A New Model for Performance Measurement in Hypertension

“…In addition, several panelists voiced concern about including self-reported home blood pressure measurements in a performance measure because machines may be miscalibrated, some patients may misreport readings, and most clinical trial data are based on blood pressures taken in a clinical setting 32,33. Thus, although panelists strongly endorsed the clinical benefits of home blood pressure monitoring, several members affirmed that performance measurement should rely largely on readings in clinical settings.…”

Considering the Inclusion of Metabolic and Cardiovascular Markers in the Panel Study of Income Dynamics

“…Perhaps most troubling is that numerous studies comparing measurements taken at home with those taken at a clinic suggest substantial discrepancies between the two: many studies reveal higher measurements at the clinic (e.g., Divison, Sanchis, Artigao, et al 2004; Narkiewicz 2007), but this is not always the case – e.g., the SEBAS study in Taiwan found that the home readings were higher than those taken at a hospital several weeks later, with correlations equal to about 0.6 between the two sets of readings. In addition, there is evidence from a study that used blood pressure devices with memory storage that, if respondents are asked to take their own measurements, they may alter the true readings or report fictitious ones (Bachmann, Steurer, Holm, & Vetter 2002). In most household surveys, determination of blood pressure is based on at least three measurements, taken by the respondent or more often a trained interviewer using an automatic device, with a brief interval between readings.…”