Table 2

Association of subjects’ symptoms with lung function

Variable	Having any respiratory symptoms			Having mMRC score ≥1
Variable	r²	OR±SEM	P values	r²	OR±SEM	P values
RV/TLC (%)	0.03	1.09±0.04	0.011	0.05	1.09±0.06	0.112
FEV₁/FVC (%)	0.03	1.07±0.04	0.045	0.03	1.01±0.06	0.882
FEV₁ (L)	0.02	0.58±0.25	0.216	0.04	0.44±0.35	0.302
FEF_25–75 (L/s)	0.02	1.10±0.24	0.681	0.03	1.06±0.40	0.875
FEF₇₅ (L/s)	0.02	1.06±0.43	0.884	0.03	1.24±0.83	0.754
TLC (L)	0.02	0.72±0.19	0.204	0.03	0.84±0.38	0.698
RV (L)	0.02	1.59±0.72	0.310	0.03	1.72±1.30	0.471
FRC (L)	0.02	0.88±0.26	0.683	0.04	1.77±0.84	0.225

The subjects’ symptoms and activity level was scored as whether they have ever reported shortness of breath, cough ≥2 episodes/year or less activity than peers. Logistic regression model of respiratory symptoms with lung functions and adjustments: OR of having symptoms=β₀+β₁(age)+β₂(sex)+β₃(height)+β₄(weight)+β₃(lung function index).
Significant P values are shown in bold. n=256.
FEF_25–75, maximum airflow at mid-lung volume; FEF₇₅, maximum airflow at low-lung volume; FEV₁, forced expiratory volume in 1 s; FRC, functional residual capacity; FVC, forced vital capacity; mMRC, modified Medical Research Council; r², model fit; RV, residual volume; TLC, total lung capacity.