Comparison of self-reported home blood pressure measurements with automatically stored values and ambulatory blood pressure

Aims: To evaluate accuracy of patient-reported home blood pressure measurements (HBPM) when compared to real HBPM and their agreement with 12-h daytime ambulatory blood pressure monitoring (ABPM). Major findings: Self-reported HBPM were compared to stored values of a fully automated, oscillometric blood pressure monitor with integrated memory device and 12-h daytime ambulatory monitoring in 54 patients. In most patients (n = 46, 85%) mean reported systolic or diastolic versus real HBPM differed by no more than 4 mmHg. In eight mostly uneducated patients (15%, 95% confidence interval, CI, 7-27%) means of reported and real HBPM differed by more than 4 mmHg (range 5-28 mmHg for systolic and 0-11 mmHg for diastolic blood pressure). Systolic agreement between self-reported HBPM and 12-h daytime ABPM was better for patients reporting greater than or equal to 80% than for patients reporting <80% of measurements correctly (mean systolic difference 0 +/- 19 versus 5 +/- 14 mmHg, respectively), whereas the opposite was true concerning agreement of diastolic blood pressure values (mean diastolic difference -6 +/- 10 and -1 +/- 9 mmHg, respectively). Conclusion: Inadequate conclusions due to poor reporting accuracy of HBPM are possible, especially in less educated patients. Thus, ABPM or automatically stored HBPM may be preferable to self-reported HBPM in these patients.