Methodological and psychological predictors of the white coat effect

The purpose of the study was to examine psychological and methodological factors which would predict the white coat effect (WCE). The WCE is defined as the difference (mm Hg) between ambulatory and office measured blood pressure (BP). Sixty three community volunteers participated in this study. Participants were divided into 3 Response style groups: (1) Office responders had ambulatory BP values which were lower than office BP, (2) Non responders showed a minimal difference between office and ambulatory BP, and (3) Home responders had significantly higher ambulatory BP compared to office BP. Participants were asked to have a series of BP readings taken by a physician, nurse and by themselves and participate in 24 hour ambulatory monitoring. State and trait self-report psychological measures were completed. Self measured BP was the most representative of ambulatory BP for the sample as a whole, and in particular for the Home responders. State anxiety, previously dismissed as mediating factor in the expression of the white coat effect, proved to discriminate between the groups. Office responders had significantly higher levels of state anxiety, directly related to BP measurements, compared to Home and Non responders. Habituation to the experience of having BP measured by a physician, and habituation of the anxiety prior to the BP measurement, was different among the three groups. Trait psychological variables did not distinguish group membership. Self measured systolic BP, state anxiety prior to self measured BP, habituation to physician measured BP and the anxiety preceding it, were entered as predictors variables in a discriminant function analyses. These variables were able to correctly classify group membership for 63% of the sample.Arts, Faculty ofPsychology, Department ofGraduat