Repeat Manual Office Blood Pressure By A Physician Is Lower Than Automated Office Blood Pressure

Introduction: An accurate measurement of blood pressure (BP) is critical to diagnosing and treating hypertension (HTN). Manual office BP (MOBP) often results in higher readings than automated office BP (AOBP). In previous studies, a repeat MOBP by a physician resulted in a lower BP than the initial MOBP by nursing staff. We evaluated our hypothesis that a repeat MOBP by a physician is statistically equivalent to AOBP. Methods: In an ambulatory outpatient setting, patients were roomed and at least a 5-minute interval lapsed before an AOBP was performed using a Welch Allyn Connex Vital Signs Monitor. The physician was blinded to the AOBP. The physician then entered the room and obtained a MOBP with a manual aneroid sphygmomanometer. The difference between the AOBP and the MOBP was calculated. A Wilcoxon signed rank sum test was used to determine if a significant difference between AOBP and MOBP exists. Results: A total of 186 patients (112 females, 74 male) had BP measured with a mean age of 66 years. AOBP resulted in a median systolic BP (SBP) 136 mmHg (IQR 121-150 mmHg) and median diastolic BP (DBP) of 78 mmHg (IQR 72-85 mmHg). MOBP SBP had a median of 132 mmHg (IQR 120-142 mmHg) and DBP had a median of 76 mmHg (IQR 70-81 mmHg). SBP and DBP were significantly lower in the MOBP group with a mean difference between AOBP and MOBP of 4.0 and 2.7 mmHg respectively (p-value of <0.0001). Conclusions: Repeat MOBP performed by the physician resulted in a significantly lower BP compared to AOBP. The lower BP may be due to an overall longer interval between the AOBP measurement and MOBP measurement. MOBP may be a viable option for accurate diagnosis and treatment of HTN clinics without access to a AOBP machine.