Authors (including presenting author) :
Chan KS, Lai KPL, Chan PF, Luk MH, Chao DVK
Affiliation :
Department of Family Medicine and Primary Health Care, United Christian Hospital and Tseung Kwan O Hospital, Kowloon East Cluster
Introduction :
The detection of white-coat effect (WCE) in patients with hypertension is important in avoiding unnecessary treatment which may lead to undesirable side effects and cost inflation. The current gold standard for the diagnosis of WCE is by the 24-hour ambulatory blood pressure monitoring (ABPM) which may not be readily available in primary care. Previous studies had shown that DBT, a relatively simple and convenient clinical maneuver, was useful in detection of the WCE through modulating the baroreceptor reflex.
Objectives :
To evaluate the diagnostic accuracy of the DBT as compared with the gold standard of 24-hour ABPM in the diagnosis of hypertension with WCE in Chinese patients in primary care.
Methodology :
Consecutive patients on anti-hypertensives, attending the Hypertension Clinic of a GOPC and with clinic systolic blood pressure (SBP) ≥140 mmHg and/or diastolic blood pressure (DBP) ≥ 90 mmHg from 1st August 2016 to 30th September 2017 were recruited. Clinic BP was recorded before and after the patients carrying out the DBT. 24-hour ABPM would be subsequently performed with reports interpreted by family medicine specialists who were blinded to the DBT results. The diagnostic accuracy of the DBT in all recruited patients, patients not taking beta-blockers and patients with different clinic SBP cut-off before the DBT by means of area under the receiver operating characteristic (ROC) curve, sensitivity, specificity, positive and negative predictive values were obtained.
Result & Outcome :
In the 178 recruited patients, the ROC curves for systolic and diastolic BP changes after the DBT were statistically non-significant. The ROC curve was statistically significant for SBP change in patients not on beta-blockers and with pre-DBT clinic SBP ≥165 mmHg (ROC curve area of 0.72, 95% CI 0.53-0.91, p=0.04). The corresponding sensitivity and specificity of the DBT were 40.9% and 90.9% respectively if SBP drop was >30mmHg. Conclusion: The DBT, though could not be clinically applied to all patients, was proven to be a potential screening and diagnostic test for WCE in Chinese hypertensive patients with a pre-test SBP of ≥165 mmHg and who were not taking beta-blockers.
Co-location with:
