THE SENSITIVITY, SPECIFICITY AND ACCURACY OF THE BpTRU VERSUS 24 HOUR AMBULATORY BLOOD PRESSURE MONITORING Author Block: D Armstrong, A Thakrar, D Brouillard, M MatangiKingston, Ontario Abstract:PURPOSE: To determine the sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and accuracy of the BpTRU electronic blood pressure (BP) measuring device when compared to average daytime 24hr ambulatory blood pressure (ABPM) measurements.METHODS: 420 consecutivepatients (P) referred for 24hr ABPM also had their BpTRU measurements recorded. The value of ≤135/85 was used as normal for both methods. The BpTRU measurements were recorded the same morning the ABPM was applied. Our BpTRU devices were set to measure 6 BP recordings every 2 minutes. The BpTRU automatically discards the first reading and averages the last 5. Our ABPM monitors record daytime BP from 7am to 10pm every half hour. Calculations were made for both systolic blood pressure (SBP) and diastolic blood pressure (DBP).RESULTS: See table 1.CONCLUSIONS: The sensitivity, specificity and accuracy of the BpTRU electronic BP measuring device when compared to average daytime 24hr ABPM is clinically unacceptable for both systolic and diastolic measurements. This device must not supplant 24hr ABPM as has been advocated by some. Table 1. SYSTOLIC BP Daytime ABPM SBP >135 Daytime ABPM SBP <136 N BpTRU SBP >135 189 44 233 PPV =81.1% BpTRU SBP <136 75 112 187 NPV =59.9% SYSTOLIC BP Sensitivity =71.6% Specificity =71.8% 420 Accuracy =71.6% DIASTOLIC BP Daytime ABPM DBP >85 Daytime ABPM DBP <86 N BpTRU DBP >85 108 62 170 PPV =63.5% BpTRU DBP <86 36 214 250 NPV =85.6 DIASTOLIC BP Sensitivity =75.0% Specificity =77.5% 420 Accuracy =76.7% :Author Disclosure Information: D. Armstrong, None; A. Thakrar, None; D. Brouillard, None; M. Matangi, None.