Evaluation of the applicability of deep breathing test in the diagnosis of hypertension with white-coat effect in Chinese patients in primary care

Table 4 Sub-group analysis of deep breathing test results with different pre-test SBP cut-off

BP response to the deep breathing test	White-coat effect		p value
BP response to the deep breathing test	Present	Absent	p value
(i) SBP ≥ 145 mmHg (N = 118)	n = 78	n = 40
Mean SBP drop (mmHg)	19.2 (SD 12.8)	14.1 (SD 12.5)	*0.042
Mean DBP drop (mmHg)	4.9 (SD 5.4)	3.8 (SD 4.3)	0.268
(ii) SBP ≥ 155 mmHg (N = 74)	n = 51	n = 23
Mean SBP drop (mmHg)	20.8 (SD 14.5)	15.1 (SD 13.0)	0.107
Mean DBP drop (mmHg)	4.8 (SD 6.3)	4.3 (SD 4.2)	0.739
(iii) SBP ≥ 165 mmHg (N = 43)	n = 30	n = 13
Mean SBP drop (mmHg)	24.4 (SD 15.4)	15.3 (SD 13.2)	0.073
Mean DBP drop (mmHg)	4.9 (SD 5.8)	3.5 (SD 3.5)	0.451
Deep breathing test operating characteristics	Area under ROC curve	95% confidence interval (CI)	p value
(i) SBP ≥ 145 mmHg (N = 118)
SBP change	0.60	0.49–0.70	0.087
DBP change	0.55	0.44–0.66	0.365
(ii) SBP ≥ 155 mmHg (N = 74)
SBP change	0.61	0.48–0.74	0.130
DBP change	0.51	0.37–0.65	0.912
(iii) SBP ≥ 165 mmHg (N = 43)
SBP change	0.68	0.51–0.84	0.070
DBP change	0.57	0.39–0.74	0.500

BP blood pressure, SBP systolic blood pressure, DBP diastolic blood pressure, DBT deep breathing test, ROC receiver operating characteristic

ISSN: 2056-5909