The impact of perceived hypertension status on anxiety and the white coat effect.

BACKGROUND: The white coat effect can lead to overdiagnosis of hypertension and unnecessary pharmacologic treatment. Mechanisms underlying the white coat effect remain poorly understood but are critical to improving the accuracy of clinic blood pressure measurement.
PURPOSE: This study investigated whether perceived hypertension status was associated with state anxiety levels during a clinic visit and the magnitude of the white coat effect, independent of true blood pressure status.
METHODS: This observational study included 214 normotensive and mildly hypertensive participants who were 18 to 80 years old, had no cardiac history, and were willing to discontinue antihypertensive medications for 8 weeks. Participants underwent 36 hr ambulatory blood pressure monitoring and physician blood pressure measurement. Outcome measures were state anxiety reported during the clinic visit and the white coat effect.
RESULTS: An analysis of covariance indicated that participants who perceived themselves as hypertensive reported greater state anxiety (p<.001) and showed larger white coat effects (ps<.01) compared with those who perceived themselves as normotensive. True hypertension status based on ambulatory blood pressure was not related to either outcome. Anxiety accounted for approximately 19% of the association between perceived hypertension status and the white coat effect.
CONCLUSIONS: These findings suggest that the perception of being hypertensive is associated with greater anxiety during clinic blood pressure measurement and a larger white coat effect, independent of the true blood pressure level. Anxiety appears to be a mechanism by which perceived hypertension status contributes to the white coat effect.