Table 1– Characteristics of the sample

	Biomass group	Tobacco group	p-value
Patient characteristics
Subjects n	21	22
Age years	69.0±6.3	69.3±5.5	0.90
Tobacco smoke exposure pack-years	0	32.6±14.4
Biomass smoke exposure hour-years	275.4±101.0	0
Height cm	148.0±6.0	154.0±3.0	0.003^#
Weight kg	61.5±12.1	61.9±10.8	0.92
BMI kg·m⁻²	28.5±6.2	26.8±4.2	0.29
Lung function
Pre-bronchodilator
FEV₁ % pred	46.7±14.9	50.3±12.2	0.38
FVC % pred	70.1±16.3	79.3±12.8	0.05
FEV₁/FVC	51.9±12.9	49.3±10.3	0.46
Post-bronchodilator
FEV₁ % pred	54.5±14.9	57.7±12.3	0.44
FVC % pred	80.6±18.6	89.0±11.8	0.08
FEV₁/FVC	53.2±11.7	50.4±9.7	0.39
Lung volumes
RV % pred	181±67	176±56	0.80
TLC % pred	130±27	125±21	0.48
RV/TLC %	0.66±0.08	0.62±0.09	0.12

Data are presented as mean±sd, unless otherwise stated. BMI: body mass index; FEV₁: forced expiratory volume in 1 s; FVC: forced vital capacity; RV: residual volume; TLC: total lung capacity.^#: nonparametric test.