Validation of the Nissei DS-400 in a low-resource setting

OBJECTIVE: Hypertension affects approximately one billion individuals worldwide. The effective management of hypertension requires accurate measurement and monitoring of blood pressure. We evaluated the accuracy of a low cost self-measurement oscillometric device, with features suitable for use in a low-resource setting, in an adult population in the developing world according to the International Protocol of the European Society of Hypertension. METHODS: Trained observers using a double-headed stethoscope took nine sequential same arm measurements from 33 participants, alternating between mercury sphygmomanometry and the test device. Anyone with an arrhythmia or unclear Korotkoff sounds was excluded. Data were analyzed according to the protocol guidelines. RESULTS: The device passed all the criteria of the International Protocol with 78/95/99 and 80/95/99 of systolic and diastolic differences, respectively, within 5/10/15 mmHg of the mercury standard. It also achieved the Association for the Advancement of Medical Instrumentation criteria with a mean difference (standard deviation) of 0.8 (4.4) mmHg and -0.9 (4.5) mmHg for systolic blood pressure and diastolic blood pressure, respectively. CONCLUSION: The Nissei DS-400 can be recommended for use in the adult population, particularly in the developing world. Its impressive performance may be related to theoretical factors within the patient population and environment (e.g. temperature, humidity and altitude) that could influence the device's performance.