Continuing to Confront COPD International Patient Survey: methods, COPD prevalence, and disease burden in 2012-2013

The Continuing to Confront COPD International Patient Survey aimed to estimate the prevalence and burden of COPD globally and to update findings from the Confronting COPD International Survey conducted in 1999-2000.

Chronic obstructive pulmonary disease (COPD) patients in 12 countries worldwide were identified through systematic screening of population samples. Telephone and face-to-face interviews were conducted between November 2012 and May 2013 using a structured survey that incorporated validated patient-reported outcome instruments. Eligible patients were adults aged 40 years and older who were taking regular respiratory medications or suffered with chronic respiratory symptoms and reported either 1) a physician diagnosis of COPD/emphysema, 2) a physician diagnosis of chronic bronchitis, or 3) a symptom-based definition of chronic bronchitis. The burden of COPD was measured with the COPD Assessment Test (CAT) and the modified Medical Research Council (mMRC) Dyspnea Scale.

Of 106,876 households with at least one person aged ≥40 years, 4,343 respondents fulfilled the case definition of COPD and completed the full survey. COPD prevalence ranged from 7% to 12%, with most countries falling within the range of 7%-9%. In all countries, prevalence increased with age, and in all countries except the US was greater among men (range 6%-14%) than among women (range 5%-11%). A significant disease burden was observed when considering COPD symptoms or health status, and showed wide variations across countries. Prevalence of moderate-to-severe dyspnea (mMRC scale ≥2) ranged from 27% to 61%, and mean CAT score ranged from 16.0 to 24.8, indicating medium-to-high impairment.

This survey, representing 12 countries, showed similar rates of estimated COPD prevalence across countries that were higher than those reported a decade ago in the original Confronting COPD International Survey. A significant burden of COPD was demonstrated by symptoms and health care-resource use, similar to that reported in the original survey.