A Simplified Screening Questionnaire for Detecting Severe OSA in Chronic Obstructive Airway Disease in Asian Population

Figures & data

Table 1. Subjects demonstration.

Characteristics	Development group n = 77	Validation group n = 78	p-value
Age, years	69.2 ± 11.5	69.4 ± 10.4	0.90
Male, n (%)	68 (88)	69 (88)	0.98
BMI, Kg/m^2	24.7 ± 4.4	24.1 ± 4.5	0.40
Cardiovascular disease, n (%)	38 (49)	42 (54)	0.58
Hypertension, n (%)	28 (36)	34 (44)	0.36
Coronary artery disease, n (%)	11 (14)	8 (10)	0.44
Atrial fibrillation, n (%)	3 (4)	6 (8)	0.30
Congestive heart failure, n (%)	5 (7)	7 (9)	0.56
Peripheral vascular disease, n (%)	1 (1)	1 (1)	0.99
Pulmonary function test
FEV1/FVC	60.2 ± 11.9	60.8 ± 11.2	0.99
FEV1 (L)	1.18 ± 0.59	1.18 ± 0.56	0.93
FEV1 (% predicted)	51.4 ± 23.8	51.7 ± 20.8	0.94
FVC (L)	1.96 ± 0.73	1.94 ± 0.68	0.87
FVC (% predicted)	61.6 ± 20.4	63.5 ± 20	0.53
AHI
Total AHI, /h	26.3 ± 21.9	27.6 ± 21.1	0.68
AHI > 30/h, n (%)	24 (32)	27 (35)	0.65

Data are presented as mean ± SD.

BMI: body mass index; FEV₁: forced expiratory volume in one second; FVC: forced volume capacity; AHI: Apnea-hypopnea index.

Table 2. Univariate severe obstructive sleep apnea predictors: (using an AHI cutoff value of 30 h^-1).

Factors	Beta estimate	SE	P value	OR
BMI ≥ 27.5 Kg/m^2	1.12	0.54	0.04	3.07
Age	0.05	0.03	0.06	1.05
Witnessed apnea	3.06	0.63	0.00	21.38
Snoring	1.68	0.68	0.01	5.37
Cardiovascular disease	0.78	0.51	0.12	2.17
Hypertension	0.58	0.5	0.25	1.79
Coronary artery disease	1.62	0.69	0.02	5.04
Atrial fibrillation	1.55	1.25	0.21	4.73
Congestive heart failure	1.29	0.95	0.17	3.64
Peripheral vascular disease	−20.0	40192	0.99	0.01

Table 3. Logistic regression analysis: factors associated with an apnea-hypopnea index ≥30/h as determined by X² automatic interaction detection analysis.

Factors	Regression coefficiency	SE	P value	OR (95% CI)
BMI ≥ 27.5 Kg/m^2	0.57	0.70	0.42	1.76 (0.45-6.93)
Witnessed apnea	2.70	0.69	0.00	14.9 (3.87-56.98)
Snoring	0.73	0.82	0.37	2.08 (0.42-10.35)
Coronary artery disease	0.37	0.85	0.66	1.45 (0.27-7.73)

BMI: body mass index.

Table 4. OSA screening questionnaire.

	If yes, SCORE
BMI: BMI ≥ 27.5	1
Witnessed Apnea: Has anyone noticed that you stop breathing during your sleep?	2
Snoring: Has your snoring ever bothered other people?	1
Coronary artery disease: Do you have coronary artery disease	1
TOTAL SCORE /5 points

OSA: obstructive sleep apnea; BMI: body mass index.

Table 5. Diagnostic performance of OSA sleep questionnaire at a variety of AHI diagnostic criterion values in development group.

	N(%)	OSA sleep questionnaire, score ≥ 2
		Sensitivity	Specificity	PPV	NPV	LR+	LR-
AHI ≥ 5	66 (85.7)	54.5%	90.1%	97.1%	25.0%	5.5	0.5
AHI ≥ 15	45(58.4)	64.0%	75.0%	78.2%	59.7%	2.6	0.5
AHI ≥ 30	24(31.2)	87.5%	69.8%	56.8%	92.5%	2.9	0.2
		OSA sleep questionnaire, score ≥ 3
		Sensitivity	Specificity	PPV	NPV	LR+	LR-
AHI ≥ 5	66(85.7)	37.9%	90.1%	95.8%	19.5%	3.8	0.7
AHI ≥ 15	45(58.4)	48.9%	87.5%	84.6%	55.0%	3.9	0.6
AHI ≥ 30	24(31.2)	75.0%	85.0%	69.3%	88.2%	5.0	0.3

OSA: obstructive sleep apnea; AHI: apnea-hypopnea index; PPV: positive predictive value; NPV: negative predictive value.

Figure 1. Receiver operating characteristic curve showing the performance of the OSA screening questionnaire, using a cutoff value of ≥ 2/5 (blue line) or ≥ 3/5 (pink line) in discriminating patients with severe OSA (AHI ≥ 30/h) in the development group (n = 77) and validation group (n = 78). AUC, area under the ROC curve.

Table 6. Diagnostic performance of OSA sleep questionnaire at a variety of AHI diagnostic criterion values in validation group.

		N(%)	OSA sleep questionnaire, score ≥ 2
			Sensitivity	Specificity	PPV	NPV	LR+	LR-
AHI ≥ 5	75(96.2)		44.0%	100.0%	100.0%	6.6%	99.9	0.6
AHI ≥ 15	52(66.7)		57.7%	88.5%	91.1%	51.1%	5.0	0.5
AHI ≥ 30	27(34.6)		85.2%	80.4%	69.7%	91.1%	4.3	0.2
			OSA sleep questionnaire, score ≥ 3
			Sensitivity	Specificity	PPV	NPV	LR+	LR-
AHI ≥ 5	75(96.2)		32.0%	100.0%	100.0%	5.5%	99.9	0.68
AHI ≥ 15	52 (66.7)		44.2%	96.2%	95.9%	45.9%	11.6	0.6
AHI ≥ 30	27(34.6)		70.8%	90.2%	79.3%	85.4%	7.2	0.3

OSA: obstructive sleep apnea; AHI: apnea-hypopnea index; PPV: positive predictive value; NPV: negative predictive value.

Table 7. Diagnostic performance of OSA sleep questionnaire at a variety of COPD severity, AHI ≥ 30.

	N(%)	OSA sleep questionnaire, score ≥ 2
		Sensitivity	Specificity	PPV	NPV	LR+	LR-
FEV1 > 80%	26(16.8)	82.8%	74.2%	39.3%	95.5%	3.2	0.2
80%≥FEV1 > 50%	60(38.7)	80.0%	68.6%	61.7%	84.5%	2.5	0.3
50%≥FEV1 > 30%	51(32.9)	72.0%	80.0%	63.8%	85.4%	3.6	0.4
30%≥FEV1	18(11.6)	66.7%	100.0%	100.0%	95.8%	99.9	0.3
		OSA sleep questionnaire, score ≥ 3
		Sensitivity	Specificity	PPV	NPV	LR+	LR-
FEV1 > 80%	26(16.8)	62.1%	87.1%	38.9%	94.5%	4.8	0.4
80%≥FEV1 > 50%	60(38.7)	60.0%	85.7%	69.4%	79.8%	4.2	0.5
50%≥FEV1 > 30%	51(32.9)	68.0%	88.6%	74.2%	85.2%	5.9	0.4
30%≥FEV1	18(11.6)	41.7%	100.0%	100.0%	86.7%	99.9	0.6