The association between transfer coefficient of the lung and the risk of exacerbation in asthma-COPD overlap: an observational cohort study

Table 3 Multivariable-adjusted odds ratios of potential risk factors for low K_CO

Variables	Number of events/cases (%)		Multivariable-adjusted OR (95% CI)	P value
	Exposure group	Reference group
Male gender	28/77 (36.4%)	4/17 (23.5%)	1.77 (0.26–13.5)	0.56
Age (per 10-year increase)	N/A	N/A	1.12 (0.52–2.41)	0.77
BMI (per 1 kg/m² increase)	N/A	N/A	0.73 (0.57–0.90)	< 0.01
FEV₁ (per 1 L increase)	N/A	N/A	1.67 (0.62–4.72)	0.32
Inhaled long-acting bronchodilator use	24/68 (35.3%)	8/26 (30.8%)	2.22 (0.25–23.1)	0.48
ICS use	21/64 (32.8%)	11/30 (36.7%)	0.74 (0.08–6.52)	0.79
COPD-like features
Smoking history ≥ 10 pack-years	30/87 (34.5%)	2/7 (28.6%)	1.84 (0.20–21.9)	0.60
Emphysema	29/64 (45.3%)	3/30 (10.0%)	7.37 (1.81–40.3)	< 0.01
Asthmatic features
Eosinophilic component	21/56 (37.5%)	11/38 (28.9%)	2.20 (0.66–8.14)	0.21
High FeNO	12/44 (27.3%)	20/50 (40.0%)	0.36 (0.09–1.23)	0.11
Positive levels for total IgE and/or IgE specific to perennial inhalant antigens	21/75 (28.0%)	11/19 (57.9%)	0.42 (0.09–1.70)	0.23
Bronchial reversibility	5/18 (27.8%)	27/76 (35.5%)	0.47 (0.09–2.15)	0.35

Adjustment was made for age, gender, BMI, FEV₁, long-acting bronchodilator use, ICS use, a smoking history of > 10 pack-years, emphysema, high FeNO, bronchial reversibility, an eosinophilic component, and positive levels for total IgE and/or IgE specific to perennial inhalant antigens. The eosinophilic component was defined as blood eosinophil ≥ 5% and/or ≥ 300/µl. High FeNO was defined as ≥ 35 parts per billion. Bronchial reversibility was defined as ≥ 12% and ≥ 200 ml reversibility in post-bronchodilator FEV₁. Positive levels for total IgE were defined as > 170 IU/ml
OR, odds ratio; 95% CI, 95% confidence interval; BMI, body mass index; FEV₁, forced expiratory volume in 1 s; ICS, inhaled corticosteroid; COPD, chronic obstructive pulmonary disease; N/A, not applicable

ISSN: 1471-2466