Use of oscillometric devices in atrial fibrillation: a comparison of three devices and invasive blood pressure measurement

Figures & data

Figure 1. Example of a measuring sequence. In this example, the first sequence is OmronR7-OmronHEM907^TM, the second is OmronR7- Microlife WatchBPHome™. In this sequence, the OmronR7 is the first device in both sequences (“device A”), both arm devices are “device B” in this example.

Table 1. Characteristics of the sample.

Variable	No ICU	ICU
N	48	10
Women (%)	23 (47.9)	4 (40.0)
Age (years)	80.4 ± 9.9	78.9 ± 9.1
Arm circumference (cm)	25.1 ± 3.1	28.7 ± 2.3
Mean systolic blood pressure(mm Hg)
Omron HEM907^TM	122 ± 19	125 ± 23
Microlife WatchBPHome^TM	122 ± 21	126 ± 24
Invasive measure	N.A	125 ± 19
Mean diastolic blood pressure (mm Hg)
OmronHEM907^TM	69 ± 11	63 ± 14
Microlife WatchBPHome^TM	72 ± 11	70 ± 15
Invasive measure	N.A	59 ± 13
Mean heart frequency
Invasive measure	N.A	96 ± 14
Diabetes (%)	16 (33.3)	3 (30.0)
Hypertension (%)	34 (70.8)	8 (80.0)
Kidney failure (%)^a	26 (54.2)	6 (66.7)

Results are expressed as average or as number of participants (percentage)^a Kidney failure was defined as a glomerular filtration of less than 60 ml/min/m². N.A: not available.

Table 2. Performance of arm devices.

	Omron HEM907^TM	Microlife WatchBPhome^TM	p-value
N of measurements per patient	5.3 ± 4.5	9.3 ± 2.3	<.001
Patients with 10 measures	17 (34.7)	43 (87.8)	<.001*
All individual measurements	260 (53.1)	455 (92.9)	<.001*

Results are expressed as average ± standard deviation or number of measurements (percentage). Between-device comparison using paired Student’s t-test or McNemar’s test (*).

Table 3. Intraclass correlations according to device (arm measurements).

	Intra-class correlation (95% CI)	Within-subject SD (mm Hg)	Intra-class correlation (mean BP values)
Omron HEM907™
Systolic	0.94 (0.90–0.97)	4.6	0.99
Diastolic	0.77 (0.67–0.89)	4.8	0.96
Microlife WatchBPhome™
Systolic	0.92 (0.88–0.96)	4.8	0.99
Diastolic	0.79 (0.69–0.89)	4.2	0.96

SD: standard deviation.

Table 4. Reliability regarding the diagnosis of hypertension between intra-arterial and peripheral blood pressure measurement.

	N	Kappa	95% CI	p-value
Omron HEM907™
All measures	57	1.00	NA	<.001
Average	7	1.00	NA	.013
Microlife WatchBPHome™
All measures	96	0.70	0.52; 0.86	<.001
Average	10	0.74	0.27; 1.00	.008

Results are expressed as Kappa values and 95% confidence interval (95% CI). NA, not assessable

Figure 2. Bland & Altman plot between Microlife WatchBPhome™ and Invasive Blood Pressure. The Microlife WatchBPhome™ systematically overestimated systolic and diastolic blood pressure.

Figure 3. Bland & Altman plot between OmronHEM907™ and Invasive Blood Pressure. The OmronHEM907™ systematically underestimated systolic and diastolic blood pressure.

Figure 4. Pearson correlation coefficient (SBP and DBP) between Microlife WatchBPHome^TM and Invasive Blood Pressure according to the number of consecutive measurements. After three consecutive blood pressure measurements, the improvement in the Pearson correlation coefficient is negligible.