Never-smokers make up >25% of the people with COPD in some studies. Who are these people? The BOLD study gathered data from 14 countries (in the U.S., Europe, Turkey, China, South Africa, Philippines and Australia), including spirometry and questionnaires on environmental exposures and symptoms from 10,000 people. Of the 4,291 never-smokers, 4% had ATS-defined COPD (5.6% by GOLD). Impressively, these never-smokers comprised 20% of the moderate-to-severe (GOLD II+) COPD cases, and 81% of them were undiagnosed. More than two-thirds were women.

They had a 72% rate of respiratory symptoms (compared to 44% for never-smokers without COPD), and they were more likely to report 10 years of exposure to indoor fires (22% vs 15%) and/or organic dusts in the workplace (19% vs 10%) than unobstructed never-smokers. COPD rates in never-smokers were highest in Australia (7.5%) and Poland (9%), and lowest in the U.S. (3.5%). A collective of drug companies are funding this ongoing study that could guide public health efforts (and drug marketing). CHEST 2011;139:752-763.