. Author manuscript; available in PMC: 2013 Oct 22.

Published in final edited form as: Eur Respir J. 2009 Aug 13;35(1):42–47. doi: 10.1183/09031936.00065009

TABLE 2.

Associations of cannabis and tobacco use with lung function at age 32 yrs

	Subjects n	Cannabis			Tobacco
		Coefficient	95% CI	p-value	Coefficient	95% CI	p-value
FEV1 mL	919	4.0	−3.7–11.8	0.311	−5.0	−10.3–0.2	0.061
FVC mL	919	12.0	3.0–21.0	0.009	0.1	−6.0–6.2	0.968
FEV1/FVC %	919	−0.08	−0.18–0.02	0.127	−0.11	−0.18– −0.04	0.003
TLC mL	883	25.0	13.9–36.0	<0.001	7.4	−0.2–14.9	0.057
FRC mL	884	15.1	4.8–25.4	0.004	10.5	3.5–17.6	0.003
RV mL	883	12.6	7.0–18.3	<0.001	6.3	2.4–10.1	0.002
Raw cmH₂O·L⁻¹·s⁻¹	884	0.014	0.002–0.026	0.024	−0.001	−0.01–0.01	0.827
sGaw mL·s⁻¹·cmH₂O⁻¹·L⁻¹	884	−3.3	−5.5– −1.0	0.005	−1.5	−3.0–0.01	0.059
Tl,co mL·min⁻¹·mmHg⁻¹	841	−0.019	−0.09–0.05	0.589	−0.130	−0.19– −0.07	<0.001
Tl,co/Va mL·min⁻¹·mmHg⁻¹·L⁻¹	841	−0.016	−0.03–	−0.01 0.003	−0.023	−0.03– −0.01	<0.001
Va mL	894	17.8	6.8–28.9	0.002	2.3	−5.2–9.9	0.545

FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; TLC: total lung capacity; FRC: functional residual capacity; RV: residual volume; Raw: airway resistance; sGaw: specific airway conductance; Tl,co: transfer factor of the lung for carbon monoxide; Va: alveolar volume. Linear regression analyses of lung function at age 32 yrs using both cannabis and tobacco exposures as predictors. All analyses adjusted for sex and, except for FEV1/FVC and sGaw, for height. Analyses of Tl,co also adjust for exhaled carbon monoxide and blood haemoglobin. Coefficients represent the difference in lung function associated with each joint-year of cannabis or pack-year of tobacco up to age 32 yrs, adjusted for use of the other substance.