The deep-breath test as a diagnostic maneuver for white-coat effect in hypertensive patients

The white-coat effect is a common phenomenon in hypertensive patients, and there is no current useful office test to detect it.

This was a cross-sectional study. We evaluated the deep-breath maneuver at the office as a diagnostic test of the white-coat effect. Participants included 83 adult patients with uncontrolled office hypertension. We measured sensitivity, specificity, likelihood ratios of different cutoff points, area under receiver operating characteristic (ROC) curve, and 95% confidence intervals. The reference standard used was 24-hour ambulatory blood pressure monitoring.

We included 73 patients [mean age, 58.7 +/- 9.5 years (mean +/- SD); 55% women]. The prevalence of white-coat effect was 62%. Comparing patients with white-coat effect versus those without, the deep-breath test resulted in a mean systolic blood pressure decrease of 17.8 and 10.9 mm Hg (P <.001) and a mean diastolic decrease of 6.6 and 5.4 mm Hg, respectively (P = not significant). The area under the ROC curve of systolic blood pressure change was 0.69 (95% confidence interval, 0.57 to 0.81). Interobserver agreement was very good.

The deep-breath test can be a helpful maneuver for the detection of white-coat effect. It has no major adverse effects and it may help avoid overtreatment and unnecessary further testing procedures.