Table 1– Odds ratios for small airway indices in 302 patients with forced expiratory volume in 1 s (FEV₁) >80% predicted

	Crude		Adjusted
	OR (95% CI)	p-value	OR (95% CI)	p-value
*FEF_25–75% <70% (n=157) versus* FEF_25–75% >70% (n=145)**
Oral steroid use	1.67 (1.04–2.68)	0.04	1.50 (0.91–2.48)	0.11
SABA use	2.00 (1.27–3.16)	0.003	1.91 (1.19–3.07)	0.007
*FEV₁/FVC <0.80 (n=167) versus* FEV₁/FVC >0.80 (n=135)**
Oral steroid use	2.06 (1.27–3.35)	0.004	1.85 (1.10–3.12)	0.02
SABA use	1.61 (1.02–2.54)	0.04	1.54 (0.95–2.51)	0.08
*R₅-R₂₀ >0.07 kPa·L⁻¹·s (n=135) versus* R₅-R₂₀ <0.07 kPa·L⁻¹·s (n=167)**
Oral steroid use	1.99 (1.23–3.19)	0.005	1.80 (1.09–2.98)	0.02
SABA use	1.83 (1.16–2.89)	0.01	1.87 (1.15–3.01)	0.01
*FEF_25–75% <70% and R₅-R₂₀ >0.07 kPa·L⁻¹·s (n=83) versus* FEF_25–75% >70% and R₅-R₂₀ <0.07 kPa·L⁻¹·s (n=93)**
Oral steroid use	2.77 (1.48–5.18)	0.001	2.34 (1.20–4.58)	0.01
SABA use	3.07 (1.66–5.67)	<0.001	3.16 (1.64–6.07)	0.001
*FEF_25–75% <70%, R₅-R₂₀ >0.07 kPa·L⁻¹·s and FEV₁/FVC <0.80 (n=72) versus* FEF_25–75% >70%, R₅-R₂₀ <0.07 kPa·L⁻¹·s and FEV₁/FVC >0.80 (n=75)**
Oral steroid use	3.29 (1.64–6.61)	0.001	2.78 (1.28–6.04)	0.01
SABA use	3.16 (1.61–6.19)	0.001	2.96 (1.44–6.12)	0.003

FEF_25–75%: forced expiratory flow at 25–75% of forced vital capacity; SABA: short-acting β-agonist; FVC: forced vital capacity; R₅: resistance at 5 Hz; R₂₀: resistance at 20 Hz.