Clinical accuracy of the Omron M3 Comfort and the Omron Evolv for self-blood pressure measurements in pregnancy and pre-eclampsia - validation according to the Universal Standard Protocol.

Background: Electronic devices for blood pressure (BP) measurements need to go through independent clinical validation as recommended by different authorities, both in general and in special populations such as pregnancy.

Objective: To evaluate the accuracy of the Omron Evolv (HEM-7600T-E) and the Omron M3 Comfort (HEM-7134-E) devices in pregnancy and pre-eclampsia according to the Universal Standard Validation Protocol.

Methods: Both devices, the Evolv and the M3 Comfort, measure BP at the brachial level using the oscillometric method. The study was performed according to the recently published protocol, the so-called "modified Advancement of Medical Instrumentation (AAMI)/British Hypertension Society (BHS)/European Society of Hypertension (ESH) protocol" or the "Universal Standard Protocol." Validation of each device included 45 pregnant women in the second and third gestational trimester of whom 15 had pre-eclampsia, 15 had gestational hypertension and 15 were normotensives. BP differences between the observer and the device BP values were classified into three categories (≤5, ≤10, and ≤15 mmHg) and the mean BP differences (test vs reference) and its SD were calculated.

Results: Both devices, the Evolv and the M3 Comfort, achieved a grade A/A in both pregnancy and pre-eclampsia. The mean difference (SD) between the mercury standard and the device BP values in pregnancy were: 1) for the Evolv of -0.7±2.3 mmHg for systolic blood pressure (SBP) and -0.1±1.8 mmHg for diastolic blood pressure (DBP); 2) for the M3 Comfort of -1.6±2.8 mmHg for SBP and -0.1±2.3 mmHg for DBP.

Conclusion: Both devices, the Evolv and the M3 Comfort, achieved a grade A/A for both SBP and DBP and fulfill the validation protocol criteria in pregnancy and pre-eclampsia. Consequently, these two devices can be recommended for home BP measurements in this specific population.