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

Abstract

Purpose: 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.

Materials and methods: 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.

Results: 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.

Conclusion: 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.

Keywords: chronic obstructive pulmonary disease; patient perspective; patient-reported outcomes; prevalence.

Figure 1

Study-consort diagram. Abbreviation: COPD, chronic obstructive pulmonary disease.

Figure 2

Estimated prevalence of chronic obstructive pulmonary disease by country. Prevalence was weighted by country size. Abbreviations: NL, Netherlands; SK, South Korea.

Figure 3

Self-reported tobacco and environmental exposure by sex. Notes: Smokers included current smokers (smoking cigarettes/cigars/pipe at least once a day) and former smokers (not currently smoking, but had smoked at least 100 cigarettes in their lifetime and at some point smoked on a daily basis). Nonsmokers included those who had smoked fewer than 100 cigarettes in their lifetime or never smoked at all. Exposed environmentally included those reporting secondhand tobacco exposure in their home or that they had lived or worked in a location for more than a year where they were exposed to dust/fumes from cooking, burning, mining, welding, or something else.

Figure 4

Patient-reported chronic obstructive pulmonary disease severity. Note: Calculated from response to the question, “Overall, how would you rate your COPD now? Is it very severe, severe, moderate, or mild?” Abbreviations: COPD, chronic obstructive pulmonary disease; NL, Netherlands; SK, South Korea.

Figure 5

Emergency room visits and hospitalizations due to chronic obstructive pulmonary disease exacerbations in past 12 months. Notes: Calculated from response to the questions, “In the past 12 months, did any of these episodes (worsening of your breathing problems) require an emergency room visit?” and “In the past 12 months, did any of these episodes (worsening of your breathing problems) require hospitalization?” Abbreviations: NL, Netherlands; SK, South Korea.