A Prediction Nomogram Combining Epworth Sleepiness Scale and Other Clinical Parameters to Predict Obstructive Sleep Apnea in Patients with Hypertension

Table 1

Characteristics of the subjects by validation set and training set.

	Training set (n = 242)	Validation set (n = 105)	Overall (347)	t/χ/z	-value
Age, year	46.60 ± 12.33	46.67 ± 12.67	46.6 ± 12.4	0.046	0.963^a
Sex, men (n, %)	182 (75.2)	88 (83.8)	270 (77.8)	3.139	0.091^b
Occupation (n, %)
Physical	82 (33.9)	30 (28.6)	112 (32.3)	3.327	0.189^b
Office work	79 (32.6)	45 (42.9)	124 (35.7)
Unclassifiable	81 (33.5)	30 (28.6)	111 (32.0)
Height (cm)	169.1 ± 7.6	168.9 ± 6.9	169.1 ± 7.4	0.291	0.763^a
Weight (kg)	79.4 ± 13.4	78.2 ± 12.6	79.0 ± 13.2	0.819	0.413^a
BMI (kg/m^2)	27.7 ± 3.7	27.3 ± 3.4	27.6 ± 3.6	0.873	0.383^a
ESS score	6.5 ± 3.8	6.3 ± 3.8	6.4 ± 3.8	0.409	0.683^a
AHI	13.4 [3.7–33.1]	10.8 [5.1–33.0]	12.1 [4.1–33.0]	0.065	0.948^c
Snoring (n, %)	214 (88.4)	91 (86.7)	305 (87.9)	0.214	0.720^b
Observed apnea (n, %)	84 (34.7)	39 (37.1)	123 (35.4)	0.189	0.714^b
Tiredness (n, %)	138 (57.0)	62 (59.0)	200 (57.6)	0.726	0.813^b
NC (cm)	40.6 ± 3.3	40.4 ± 2.8	40.5 ± 3.1	0.283	0.778^a

OSA: Obstructive sleep apnea; BMI: body mass index; ESS: Epworth sleepiness scale; AHI: apnea-hypopnea index; NC: neck circumference. Mean ± SD, median (25th and 75th percentiles), or N (column %). P values: a = t-test, b = Pearson's chi-square test, and c = Wilcoxon rank-sum test.