Evaluation on the White Coat Effect in Consulting Room Through Automatic Office Blood Pressure Monitoring

Objective To evaluate the effect of physician's presence and corresponding factors on blood pressure(BP)in consulting room through automatic office blood pressure(AOBP)monitoring.Methods Two hundred and forty-three patients(117 male,126 female)treated in the department of cardiology,second hospital affiliated to Nanchang university were enrolled in this study.These cases were divided into hypertension group(n=144)and without hypertension group(n=99)according to systolic BP(SBP)≥140 mm Hg and(or)diastolic BP(DBP)≥90 mm Hg,or to the history of hypertension.BP was monitored with the same automatic measuring device.The average of 2 BP readings was recorded as BP1 when the physician was firstly present,and the mean of 5 BP measurement values was labeled as AOBP in the absence of physician,and then the average of 2 BP measurements was defined as BP2 when the physician made his second appearance.The differences between BP1 and AOBP,between BP2 and AOBP were termed as ΔBP1(ΔSBP1 and ΔDBP1)and ΔBP2(ΔSBP2 and ΔDBP2),respectively.ΔBP1/BP1 and ΔBP2/BP1 ratios were also analyzed.Results ① SBP1 and DBP1,as well as SBP2 and DBP2 were significantly higher than AOSBP and AODBP respectively(P0.01).②ΔSBP1 [(8.3±0.8)vs(4.6±0.9)mm Hg],ΔSBP2[(2.7±0.7)vs(0.7±0.7)mm Hg)and ΔDBP2 [(3.4±0.6)vs(2.9±0.6)mm Hg] were significantly increased in the patients with hypertension than those without hypertension.③In the cases without hypertension,ΔBP1/BP1 and ΔBP2/BP1 were significantly larger in female than in male.Conclusion BP measurements of patients are increased in the presence of physician,even at the moment of second contact.Female and hypertension are facilitating factors to the white coat effect.