Wrist blood pressure-measuring devices: a comparative study of accuracy with a standard auscultatory method using a mercury manometer

Background In this study, we compared two wrist blood pressure-measuring devices, the Omron RX and the Nissei WS-310, against a mercury manometer. Method A total of 152 subjects attending an out-patient hypertensive clinic were recruited from a randomized blood pressure survey, 87 patients (mean 44.4 +/- 14.5 years of age) being selected according to the Association for the Advancement of Medical Instrumentation/British Hypertension Society standards. Device validation was assessed through the use of sequential same-arm readings compared with readings taken using a mercury sphygmomanometer by the two trained observers. Results There were no differences between the observers and the monitors for diastolic readings (2.8 +/- 4.8 mmHg for the Omron and 4.2 +/- 6.4 mmHg for the Nissei) according to the Association for the Advancement of Medical Instrumentation standards. The largest standard deviations - 8.3 mmHg for the Omron and 8.8 mmHg for the Nissei, respectively were seen for systolic readings recorded by the observers and the monitors. According to the British Hypertension Society standards, the Omron achieved an A grade for diastolic readings and a B grade for systolic readings within 5 and 10 mmHg. The Nissei monitor achieved an A grade for diastolic readings and a B grade for systolic readings within 5 and 10 mmHg. Conclusion Patients found the wrist oscillometric devices that we tested to be comfortable and easy to use. These devices are appropriate for measuring diastolic blood pressure according to the standards, but the reliability of both devices decreased when measuring systolic blood pressure. (C) 2002 Lippincott Williams Wilkins.