title: Janus faces of the white coat effect: blood pressure not only rises, it may also fall.
abstract: For reliable control of hypertension, it is essential to know the prevalence of the white coat effect (WCE), which is defined as either a difference of 10 mmHg or more in systolic blood pressure (BP) and/or a difference of 5 mmHg or more in diastolic BP measured by a general practitioner (GP), a nurse, or the patient him/herself. The objective was to assess the WCE in hypertensive patients visiting GPs in primary healthcare centres. A blinded, randomised study in six primary healthcare centres was conducted, where eight GPs, nine nurses and 210 patients (92 men and 118 women) on a hypertension control regimen participated. Heart rate and BP in GPs', nurses' and self-service rooms were measured twice using a sphygmomanometer and an automatic device. Altogether, 148 patients (70%) performed the self-measurements of BP and heart rate perfectly successfully in all the three rooms. These were included in the final analyses. One out of three patients (33%) showed a marked alerting WCE in the GP's room (systolic BP rose by at least 10 mmHg and/or diastolic BP by at least 5 mmHg). On the contrary, one out of 10 (10%) showed a marked relaxing WCE in the GP's room (systolic BP decreased by at least 10 mmHg and/or diastolic BP by at least 5 mmHg). It can be concluded that the WCE in general practice has two faces: an alerting reaction and a relaxing reaction. This should be taken into account in hypertension control.
authors.affiliation: Department of Public Health and General Practice, Kuopio University, Finland, and General Practice, Kuopio University Hospital, Kuopio, Finland. Esko.kumpusalo@uku.fi
authors.forename: E
authors.initials: E
authors.lastname: Kumpusalo
authors.forename: A
authors.initials: A
authors.lastname: Teho
authors.forename: R
authors.initials: R
authors.lastname: Laitila
authors.forename: J
authors.initials: J
authors.lastname: Takala
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination / Q000379:methods; D005194:Family Practice; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009819:Office Visits