Strengths and Limitations
One major strength of this study is that the findings can be directly
translated into everyday practice. Due to the adjustments we made to the
original ESH-IP 2010, this study provides valuable information
concerning the implications of the use of such a device in clinical
practice. Along with research this study also has some potential
methodological imperfections that need to be addressed. First, we did
not perform a validation study following the strict criteria the ESH-IP
2010 protocol. Critics might say that the CDXP needs a validation before
it can be used in daily practice. However, we showed that the margins of
difference from the gold standard are comparable to the validated Omron
M6 Comfort. Therefore, we think our data show that the CDXP is just as
reliable. Second, it was necessary to adjust the blood pressure ranges
of the ESH-IP 2010 to make it directly applicable on a pregnant
population, as normal blood pressure ranges strongly differ from a
non-pregnant population9. Third, we used one
non-blinded observant taking all the measurements instead of two blinded
observants as proposed by the ESH-IP 2010. However, as the observant
measured the aneroid blood pressure before the device measurements we do
not think this influenced our results. Fourth, in phase 1 and 2 we used
different reference devices (Omron M6 Comfort and Welch Allyn 5300P) to
compare to the CDXP. Although both reference devices have been validated
in pregnancy, this theoretically might have induced small differences
between the two phases. However, we do not think this to be clinically
relevant. We think the CDXP can be used for HBPM during pregnancy.