Validation of the Braun BP 3550 wrist blood pressure measuring device with a position sensor and an EasyClick cuff according to the International Protocol in adults

Objective Among the electronic blood pressure measuring devices used for self-measurement of blood pressure by patients, models that measure at the wrist are becoming increasingly popular. Validation studies done with these equipments, however, are quite few. The objective of this study was to evaluate the accuracy of the Braun BP 3550 wrist blood pressure device against the mercury sphygmomanometer in adults according to the International Protocol criteria. Methods Fifty-four patients over 30 years of age were studied and classified on the basis of the range of the International Protocol. Blood pressure measurements at the wrist with the Braun BP 3550 were compared with the results obtained by two trained observers using a mercury sphygmomanometer. Nine sequential blood pressure measurements were taken. A total of 33 individuals with randomly distributed arm circumferences were selected for the validation study. During the validation study, 99 measurements were obtained for comparison from 33 individuals. The first phase was performed on 15 individuals and if the device passed this phase, 18 more individuals were selected. Results Mean discrepancies and standard deviations of the device sphygmomanometer were 0.4 +/- 8.1 mmHg for systolic blood pressure and 2.1 +/- 5.8 mmHg for diastolic blood pressure in the study group. The device passed phase 1 in 15 individuals. In phase 2.1, from the total 99 comparisons, 65, 84 and 91 for systolic blood pressure and 62, 91 and 98 for diastolic blood pressure were <5, < 10 and < 15 mmHg, respectively. In phase 2.2, 23 individuals had at least two of the differences within 5 mmHg, and two had no differences within 5 mmHg for systolic blood pressure. In terms of diastolic blood pressure, 23 individuals had at least two of the differences within 5 mmHg and three had no differences within 5 mmHg. Braun BP 3550 passed phases 2.1 and 2.2 in the adult participants. Conclusion The Braun BP 3550 wrist blood pressure device passed according to the International Protocol criteria and can be recommended for use in adults. Deviation from the average value, however, was greater in patients with high systolic blood pressure as compared with those with lower blood pressure.