White coat hypertension: is it all just in the look?

I have recently done a study for my regional science fair on white coat hypertension in 50 random patients at a local cardiovascular clinic. Participants’ blood pressure was measured by a cardiologist, a nurse, and a cardiovascular technician. Each healthcare provider measured blood pressure in the same manner twice, one measurement with a white lab coat, and one measurement without a white lab coat in a randomised order. Participants had an automated 24-hour ambulatory blood pressure monitor (ABPM) reading which served as the control for this study. The difference between the average reading of the systolic blood pressure assessed by ABPM and the average reading of systolic blood pressure assessed by the cardiologist was 23.7 mmHg with a white lab coat and 13.3 mmHg without a white lab coat (P<0.001). The difference between the average reading of the systolic blood pressure assessed by ABPM and the average reading of systolic blood pressure assessed by the nurse was 14.2 mmHg with a white lab coat, and 5.7 mmHg without a white lab coat (P<0.001). The difference between the average reading of the systolic blood pressure assessed by ABPM and the average reading of systolic blood pressure assessed by the cardiovascular technician was 2.8 mmHg with a white lab coat, and −1.8 mmHg without a white lab coat (P<0.001). This suggests that blood pressure recordings are most erroneous when done by a physician, than by a nurse, and most closely match the gold standard of ABPM when done by a cardiovascular technician, and that wearing a white lab coat also exaggerates the effects of the white coat syndrome. Both the study I performed and the study in your journal demonstrate that when doctors measure blood pressure, the readings may be more erroneous than if measured by a nurse, a cardiovascular technician, or ABPM. Perhaps clinics should have blood pressure measured by allied healthcare professionals not wearing a white coat to reduce the risk of erroneous readings.