Table 3. Results.

Mean blood pressure
Range [mmHg]	Patients/ Pairs [n]	Bias [mmHg]	Precision (95%CI) [mmHg]
entire	128/335	-0.35	12.0 (10.6, 14.1)
< 30	67/146	1.01	10.7 (8.8, 13.1)
30–40	58/117	0.92	12.6 (10.4, 15.7)
> 40	50/72	-2.52	12.0 (9.5, 15.3)
Systolic blood pressure
Range [mmHg]	Patients/ Pairs [n]	Bias [mmHg]	Precision (95%CI) [mmHg]
entire	128/335	6.21	15.9 (15.0, 20.0)
< 35	58/95	9.89	15.6 (12.7, 19.5)
35–50	70/151	7.24	15.5 (13.0, 19.0)
> 50	52/89	1.37	14.6 (11.9, 18.4)
Diastolic blood pressure
Range [mmHg]	Patients/ Pairs [n]	Bias [mmHg]	Precision (95%CI) [mmHg]
entire	128/335	-4.21	12.8 (11.2, 14.9)
< 20	48/99	-2.31	11.2 (8.9, 14.3)
20–30	66/146	-3.52	11.3 (9.4, 13.8)
> 30	64/90	-5.45	14.9 (12.2, 18.4)

Difference of invasive and non-invasive blood pressure readings in preterm infants (gestational age < 28 weeks) for different blood pressure ranges. (CI, Confidence interval).