Diagnostic Accuracy Comparison between Automatic and Conventional Blood Pressure Measuring Devices in Adults with Hypertension

Background Blood pressure measurement is a main clinical procedure used for the detection of Systemic Arterial Hypertension. Mercury sphygmomanometer, in combination with auscultation technique, is still recognized as the gold standard for non-invasive blood pressure measurement. Objective The objective of this study is to compare the diagnostic accuracy between automatic non-invasive blood pressure measurement devices versus mercury sphygmomanometers in hospitalized patients. Methods A prospective, analytical and cross-sectional diagnostic method study was designed to compare the concordance, positive and negative predictive value, the sensitivity and specificity of automatic non-invasive blood pressure measurement devices and the mercury sphygmomanometer. The devices were divided into two groups: the reference standard which was mercury sphygmomanometer (n=150), versus the index tests, that were wrist device (n=150), semi-automatic sphygmomanometer (n=150) and vital signs monitor (n=150). Results The monitor detected more cases (69%) of systemic arterial hypertension (p 0.0019, OR 5.3). The semiautomatic sphygmomanometer identified more true positives (n=22) and true negatives (n=113). It also showed a higher diagnostic accuracy: 67% sensitivity (p 0.0576, OR 0.5) and 97% specificity (p 0.088, OR 3.2). A mean arterial pressure variation <5mmHg of 65% was found with the semiautomatic sphygmomanometer ( p <0.0001, OR 0.02) and 61% with the vital signs monitor ( p <0.0001, OR 0.12). Best concordance of blood pressure between reference standard versus index test was obtained in the following order: Semi-automatic sphygmomanometer, Vital signs monitor, and Wrist device. Conclusion The use of vital signs monitor to measure blood pressure is recommended in all patients, although semiautomatic sphygmomanometer is more sensitive for the detection of systemic arterial hypertension.