Rationale: The demographic, physiologic, and computed tomography (CT) features associated with pneumothorax in smokers with and without chronic obstructive pulmonary disease (COPD) are not clearly defined.

Objectives: We evaluated the hypothesis that pneumothorax in smokers is associated with male gender, tall and thin stature, airflow obstruction, and increased total and sub-pleural emphysema.

Methods: The study included smokers with and without COPD from the COPDGene study, with quantitative chest CT analysis. Pleural-based emphysema was assessed using local histogram measures of emphysema. Pneumothorax history was defined by subject self-report.

Measurements and Main Results: Pneumothorax was reported in 286 (3.2%) of 9,062 participants. In all participants, risk of prior pneumothorax was significantly higher in men (OR 1.55, 95% CI 1.08 - 2.22) and non-Hispanic whites (OR 1.90, 95% CI 1.34 - 2.69). Risk of prior pneumothorax was associated with increased percent CT emphysema in all participants and participants with COPD (OR 1.04 for each 1% increase in emphysema, 95% CI 1.03 - 1.06). Increased pleural-based emphysema was independently associated with risk of past pneumothorax in all participants (OR 1.05 for each 1% increase, 95% CI 1.01 - 1.10). In smokers with normal spirometry, risk of past pneumothorax was associated with non-Hispanic white race and lifetime smoking intensity (OR 1.20 for every 10 pack-years, 95% CI 1.09 - 1.33).

Conclusions: Among smokers, pneumothorax is associated with male gender, non-Hispanic white race, and increased percentage of total and sub-pleural CT emphysema. Pneumothorax was not independently associated with height or lung function, even in participants with COPD. ClinicalTrials.gov Identifier: NCT00608764.