Table 1.

Study cohort characteristics are stratified by respiratory failure in patients with acute exacerbation of COPD

Characteristic	Respiratory Failure (N = 48)		No Respiratory Failure (N = 76)		P Value
	N	Value	N	Value
Agea	48	66.0(62.3,72.8)	76	70.0(63.3,73.0)	0.13
Female genderb	39	81.3%	65	85.5%	0.62
BMIa	48	20.8(17.3,22.4)	76	21.2(18.4,22.9)	0.18
Smoking Index a	48	600(0,975)	76	675(363,1350)	0.32
Duration of COPDa	48	13(6,29)	76	10(6,20)	0.31
Comorbiditiesb	24	50.0%	41	53.9%	0.71
Diabetes mellitusb	7	14.6%	7	9.2%	0.39
Coronary diseaseb	3	6.3%	5	6.6%	1.00
Strokeb	0	0%	3	3.9%	0.28
Hypertensionb	21	43.8%	37	48.7%	0.71
Home oxygen therapyb	26	54.2%	20	26.3%	0.002
Regular medicationb	29	60.4%	40	52.6%	0.46
Oral glucocorticoid therapyb	3	6.3%	2	2.6%	0.37
Theophylline therapyb	1	2.1%	1	1.3%	1.00
Expectorants therapyb	16	33.3%	18	23.7%	0.30
Inhaled COPD therapyb		-	-	-	0.25
No inhaled treatmentb	5	10.4%	15	19.7%
LAMAb	3	6.3%	6	7.9%
ICS + LABAb	5	10.4%	15	19.7%
LABA + LAMAb	7	14.6%	9	11.8%
ICS + LABA + LAMAb	28	58.3%	31	40.8%
SGRQ scorea	48	50.5(35.1,74.1)	76	37.2(25.4,58.5)	0.003
mMRC scorea	48	2(1,3)	76	1(1,3)	0.006
Exercise capacity scorea	48	2(1,2)	76	1(1,2)	0.003
CAT scorea	48	26(21,32)	76	19(13,26)	0.0002
COPD-related exacerbation within the previous yeara	48	1(0,2)	76	0(0,1)	0.019

COPD chronic obstructive pulmonary disease, BMI body mass index, LAMA Long-acting muscarinic antagonists, LABA long-acting beta2-agonists, ICS inhaled corticosteroids, SGRQ St George's respiratory questionnaire, mMRC modified medical research council, CAT chronic obstructive pulmonary disease assessment test

Data are expressed as

^amedian; 25–75th percentile

^bdata are expressed as %. P values: to evaluate the differences between the two groups, an independent t-test was used to analyze the normally distributed continuous variables; the Mann–Whitney U test was used to analyze the non-normally distributed variables; and Chi-square (χ2) tests were used to analyze the categorical variables