Table 4.

Multivariate logistic regression analysis of risk factors for COPD coexisting OSA (AHI > 15 times per hour)

Variables	β	Wald	P	OR	95% CI
BMI (kg/m2)	0.161	26.794	< 0.001	1.175	1.104 ~ 1.251
Neck circumference	0.101	4.251	< 0.001	1.099	1.013 ~ 1.211
FEV1	0.023	2.086	0.149	1.023	0.991 ~ 1.057
FEV1 (%predicted) < 50%	− 0.549	5.893	0.045	0.578	0.392 ~ 0.782
CAT scores	0.187	30.154	< 0.001	1.195	1.112 ~ 1.288
ESS scores	0.118	7.667	< 0.001	1.113	1.052 ~ 1.177
SBQ scores	0.188	13.866	< 0.001	1.206	1.119 ~ 1.301
HADS-A	0.201	27.956	< 0.001	1.275	1.126 ~ 1.432
HADS-D	0.198	28.012	< 0.001	1.243	1.120 ~ 1.401
Hypertension	0.309	30.442	0.037	1.831	1.357 ~ 2.321
Coronary heart disease	0.111	3.458	0.053	1.117	0.999 ~ 1.249
Diabetes	0.311	34.521	< 0.001	1.852	1.421 ~ 2.312

Overlap syndrome (AHI > 15 times per hour) was considered as the dependent variable and age, BMI, neck circumference, FEV₁, FEV₁(%predicted) < 50%, CAT score, ESS score, SBQ scores, HADS-A scores, HADS-D scores, hypertension, coronary heart disease and diabetes as independent variables. BMI body mass index; FEV₁ forced expiratory volume in 1 s; CAT COPD assessment test; ESS Epworth sleepiness scale; SBQ STOP-Bang; HADS-A Hospital Anxiety and Depression Scale for anxiety; HADS-D Hospital Anxiety and Depression Scale for depression.