Table. 4—

Multiple linear regressions devised on the overall population

	EFL		Delta TMEF		FEV₁/FVC
	β±se	p-value	β±se	p-value	β±se	p-value
Sex	0.07±0.05	0.20	−13.48±5.98	0.02	1.57±0.94	0.09
Age	0.01±0.00	0.19	−0.70±0.44	0.11	0.00±0.07	0.95
Height	0.00±0.00	0.58	0.33±0.33	0.32	−0.07±0.05	0.17
Dyspnoea	0.19±0.06	0.00	−15.27±6.67	0.02	−2.64±1.05	0.01
Wheezing	0.20±0.08	0.02	−11.43±9.28	0.22	−4.87±1.46	0.00
Cough	0.02±0.09	0.79	−3.61±9.59	0.71	2.52±1.51	0.10
Sputum	-0.06±0.10	0.50	−4.12±10.52	0.70	−1.63±1.65	0.32
Asthma	0.07±0.07	0.36	−9.82±8.02	0.22	−4.43±1.26	0.00
Smoking status	0.09±0.07	0.21	−14.56±8.19	0.08	−1.08±1.29	0.40
Constant	0.26±0.61	0.67	83.77±67.05	0.21	88.71±10.53	0.00
Adjusted r²	0.038		0.048		0.075

EFL: expiratory flow limitation; TMEF: the mean-mid expiratory flow between 25 and 75% of tidal volume; FEV₁: forced expiratory volume in one second; FVC: forced vital capacity; r²: coefficient determination.