Validation of the mobil-O-Graph: 24 h-blood pressure measurement device

Abstract

Objective: Twenty-four-hour blood pressure measurement is of importance not only in the detection of hypertension but also in the detection of blood pressure changes in hypertensive and nonhypertensives over the day to identify, for example, nondipper hypertensives. This study describes the validation of the mobil-O-Graph according to the criteria of the British Hypertension Society (BHS).

Methods: For each patient three readings obtained by the mobil-O-Graph were compared with auscultatory sphygmomanometric readings obtained by two trained clinicians. The sphygmomanometric reference measurements were alternated with the readings obtained by the device. Eighty-five patients (mean age 53.4+/-18.4 years) were recruited for the BHS protocol. Differences between blood pressure values of the test device and the mercury reading were calculated for each measurement.

Results: In the BHS validation procedure the mean differences of the observer readings and the test device were -2.2+/-6.7 (systolic) and -0.6+/-5.6 mmHg (diastolic) for observer 1 and -2.2+/-7.3 mmHg (systolic) and-0.4+/-6.1 mmHg (diastolic) for observer 2. The device achieved grade A for systolic and diastolic blood pressure for both the observers 1 and 2 leading to a final grade A/A. According to the BHS protocol the measurements of the device have to be considered 'very accurate and with no error of clinical relevance'.

Conclusion: The device met the accuracy requirements of the BHS standard and can be recommended for clinical use.