Comparison of attended with unattended blood pressure measurements performed by two different devices

Objective: Unattended blood pressure (uBP) is lower than blood pressure (BP) measured by physician or nurse (attended blood pressure, aBP). We aimed to compare the uBP values obtained in two population-based cohorts, where uBP was measured in different way. Design and method: In the MONICA Study, 1% random samples from general population were repeatedly examined. We selected two cohorts for the present analysis: cohort 1 (examined in 2016, n = 179), where uBP was measured by BPTru (six measurements, first skipped, with no pause before the measurements), and cohort 2 (year 2018, n = 166) where uBP was measured by Omron 907 (three measurements after a preset 5-minute pause). aBP was measured after uBP in triplicate by physician using auscultatory method. Results: The two cohorts did not differ in age (67 vs 69 years), sex distribution, prevalence of cardiovascular disease, prevalence of hypertension (74 vs 73%), atrial fibrillation, diabetes, antihypertensive or hypolipidemic treatment and smoking. Systolic aBP was 137.6 ± 16.6 vs 135.4 ± 17.8 mmHg (NS) and diastolic aBP was 81.4 ± 9.4 vs 77.2 ± 9.5 mmHg (<0.0001) in the two cohorts, respectively. Differences between aBP and uBP were significant in all cases (p < 0.001), ranging from 3.7 mmHg (diastolic aBP – BP by Omron) to 8.8 mmHg (systolic aBP – BPTru). When the BPTru and Omron uBP measurements were compared, no difference was found. This was true when the means of all measurements were compared (five by BPTru and three by Omron) and also when only two measurements were analyzed (2nd and 3rd one, available for both devices). Multiple regression of systolic aBP – uBP difference showed that the only significant determinant was aBP value (positive association, p < 0.0001). Conclusions: There was no difference between the uBP values measured by BPTru and Omron 907. The 2nd and 3rd measurements seem to be sufficient to be taken into account.