Table 2.

Prevalence, Kappa statistic and overall agreement for classification of daytime hypertension, nighttime hypertension, non-dipping status, and magnitude of dipping blood pressure categories using times derived from self-report, fixed-time periods^† and actigraphy from ambulatory blood pressure monitoring period 1 (n = 330).

	Overall (%)	No	No	Yes	Yes	Kappa Statistic (95% confidence interval)	Overall percent agreement (95% confidence interval)
	Overall (%)	No (%)	Yes (%)	No (%)	Yes (%)	Kappa Statistic (95% confidence interval)	Overall percent agreement (95% confidence interval)

Daytime hypertension

Self-reported	17.9	80.0	2.1	1.2	16.7	0.89 (0.82 – 0.95)	0.97 (0.95 – 0.99)
Fixed-time	18.8	80.0	2.1	1.2	16.7	0.89 (0.82 – 0.95)	0.97 (0.95 – 0.99)

Self-reported	17.9	82.1	0.0	0.0	17.9	1.00 (0.98 – 1.00)	1.00 (0.99 – 1.00)
Actigraphy	17.9	82.1	0.0	0.0	17.9	1.00 (0.98 – 1.00)	1.00 (0.99 – 1.00)

Fixed-time	18.8	80.0	1.2	2.1	16.7	0.89 (0.82 – 0.95)	0.97 (0.95 – 0.99)
Actigraphy	17.9	80.0	1.2	2.1	16.7	0.89 (0.82 – 0.95)	0.97 (0.95 – 0.99)

Nighttime hypertension

Self-reported	30.0	65.8	4.2	2.1	27.9	0.85 (0.79 – 0.91)	0.94 (0.91 – 0.96)
Fixed-time	32.1	65.8	4.2	2.1	27.9	0.85 (0.79 – 0.91)	0.94 (0.91 – 0.96)

Self-reported	30.0^**	69.7	0.3	3.3	26.7	0.91 (0.86 – 0.96)	0.96 (0.94 – 0.98)
Actigraphy	27.0	69.7	0.3	3.3	26.7	0.91 (0.86 – 0.96)	0.96 (0.94 – 0.98)

Fixed-time	32.1^**	67.3	0.6	5.8	26.4	0.85 (0.79 – 0.91)	0.94 (0.91 – 0.96)
Actigraphy	27.0	67.3	0.6	5.8	26.4	0.85 (0.79 – 0.91)	0.94 (0.91 – 0.96)

Non-dipping status (2-groups)

Self-reported	37.6	57.3	5.2	5.8	31.8	0.72 (0.64 – 0.91)	0.89 (0.86 – 0.92)
Fixed-time	37.0	57.3	5.2	5.8	31.8	0.72 (0.64 – 0.91)	0.89 (0.86 – 0.92)

Self-reported	37.6^*	60.6	1.8	5.2	32.4	0.85 (0.79 – 0.91)	0.93 (0.90 – 0.96)
Actigraphy	34.2	60.6	1.8	5.2	32.4	0.85 (0.79 – 0.91)	0.93 (0.90 – 0.96)

Fixed-time	37.0	57.9	5.2	7.9	29.1	0.77 (0.69 – 0.84)	0.87 (0.83 – 0.91)
Actigraphy	34.2	57.9	5.2	7.9	29.1	0.77 (0.69 – 0.84)	0.87 (0.83 – 0.91)

Magnitude of dipping status (4-groups)

Extreme dipping

Self-reported	5.8^**	89.1	5.2	1.5	4.2	0.53 (0.35 – 0.70)	0.93 (0.91 – 0.96)
Fixed-time	9.4	89.1	5.2	1.5	4.2	0.53 (0.35 – 0.70)	0.93 (0.91 – 0.96)

Self-reported	5.8	93.9	0.3	0.3	5.5	0.94 (0.87 – 1.00)	0.99 (0.99 – 1.00)
Actigraphy	5.8	93.9	0.3	0.3	5.5	0.94 (0.87 – 1.00)	0.99 (0.99 – 1.00)

Fixed-time	9.4^**	89.1	1.5	5.2	4.2	0.53 (0.35 – 0.70)	0.93 (0.91 – 0.96)
Actigraphy	5.8	89.1	1.5	5.2	4.2	0.53 (0.35 – 0.70)	0.93 (0.91 – 0.96)

Dipping

Self-reported	56.7	36.1	7.3	10.3	46.4	0.65 (0.56 – 0.73)	0.82 (0.78 – 0.87)
Fixed-time	53.6	36.1	7.3	10.3	46.4	0.65 (0.56 – 0.73)	0.82 (0.78 – 0.87)

Self-reported	56.7^*	38.2	5.2	1.8	54.9	0.86 (0.80 – 0.91)	0.93 (0.90 – 0.96)
Actigraphy	60.0	38.2	5.2	1.8	54.9	0.86 (0.80 – 0.91)	0.93 (0.90 – 0.96)

Fixed-time	53.6^**	33.6	12.7	6.4	47.3	0.61 (0.53 – 0.70)	0.81 (0.77 – 0.85)
Actigraphy	60.6	33.6	12.7	6.4	47.3	0.61 (0.53 – 0.70)	0.81 (0.77 – 0.85)

Non-dipping

Self-reported	34.6	60.0	5.5	8.5	26.1	0.69 (0.60 – 0.77)	0.86 (0.82 – 0.90)
Fixed-time	31.5	60.0	5.5	8.5	26.1	0.69 (0.60 – 0.77)	0.86 (0.82 – 0.90)

Self-reported	34.6	63.0	2.4	5.2	29.4	0.83 (0.77 – 0.89)	0.92 (0.90 – 0.95)
Actigraphy	31.8	63.0	2.4	5.2	29.4	0.83 (0.77 – 0.89)	0.92 (0.90 – 0.95)

Fixed-time	31.5	61.5	7.0	6.7	24.9	0.68 (0.60 – 0.77)	0.86 (0.83 – 0.90)
Actigraphy	31.8	61.5	7.0	6.7	24.9	0.68 (0.60 – 0.77)	0.86 (0.83 – 0.90)

Reverse dipping

Self-reported	3.0^*	93.3	3.6	1.2	1.8	0.41 (0.17 – 0.64)	0.95 (0.93 – 0.97)
Fixed-time	5.5	93.3	3.6	1.2	1.8	0.41 (0.17 – 0.64)	0.95 (0.93 – 0.97)

Self-reported	3.0	96.7	0.3	0.9	2.1	0.77 (0.55 – 0.99)	0.99 (0.98 – 1.00)
Actigraphy	2.4	96.7	0.3	0.9	2.1	0.77 (0.55 – 0.99)	0.99 (0.98 – 1.00)

Fixed-time	5.5^**	93.9	0.6	3.6	1.8	0.44 (0.20 – 0.68)	0.96 (0.94 – 0.98)
Actigraphy	2.4	93.9	0.6	3.6	1.8	0.44 (0.20 – 0.68)	0.96 (0.94 – 0.98)

Daytime hypertension is defined as daytime systolic or diastolic blood pressure ≥135 or ≥85 mmHg at ambulatory blood pressure monitoring period 1.

Nighttime hypertension is defined as a nighttime systolic or diastolic blood pressure ≥120 or ≥70 mmHg at ambulatory blood pressure monitoring periods 1.

Non-dipping status defined as night-day BP ratio is >0.90 at ambulatory blood pressure monitoring periods 1.

Magnitude of dipping defined as 4 categories (must be present at ambulatory blood pressure monitoring periods 1: extreme dipper (mean night-day BP ratio ≤0.80), dipper (mean night-day BP ratio >0.80 and ≤0.90), non-dipper (mean night-day BP ratio >0.90 and ≤1.00), and reverse dipper (mean night-day BP ratio >1.00).

Indicates p-value ≤0.05 using McNemar’s chi-square test for paired proportions.

^**

Indicates p-value ≤0.01 using McNemar’s chi-square test for paired proportions.

^†

Using the definition of the International Database of Ambulatory Blood Pressure in relation to Cardiovascular Outcome (IDACO) for Europeans (nighttime: 00:00 to 06:00; daytime: 10:00 to 20:00).