© 2007 American Thoracic Society doi: 10.1164/rccm.200706-927ED
Breaking Down the "Great Wall" of COPD Care in ChinaJames Hogg iCAPTURE Center, St. Paul's Hospital and University of British Columbia, Vancouver, Canada China is the world's leading producer and consumer of tobacco products with more than 34.8 million cartons of cigarettes produced and 34.7 million sold each year (1). Today, there are more than 320 million smokers in China, representing 67% of the total adult male and 4% of the adult female populations in that country. Approximately one-third of all smokers in the world are Chinese (1). Not surprisingly, smoking-related lung diseases and, in particular, chronic obstructive pulmonary disease (COPD) are a major epidemic in China, costing that society billions of dollars in health care expenditures and lost productivity from premature (and perhaps unnecessary) deaths every year (2). In 2000, the total cost of COPD and other smoking-related diseases in China was more than U.S. $5 billion (2) and, in 2000, COPD was the second leading cause of mortality in China, trailing only cerebrovascular disease (3). The morbidity and mortality from COPD in China will grow exponentially in the coming years, driven in part by the aging of the population, continued increases in smoking rates, especially in women, and the successful treatment of other common disorders, such as cardiovascular and infectious diseases (4). Despite these alarming statistics, robust prevalence estimates of COPD in China have not been available until now. In this issue of the AJRCCM (pp. 753–760), Zhong and colleagues report the findings from the largest COPD prevalence study of its kind in China (5). The study was conducted in over 20,000 residents across seven different provinces and cities representing more than 230 million people (5). They found that approximately 8.2% of subjects who were 40 years and older had spirometric evidence of COPD and, of these, 75% (5.9% of the total subjects tested) demonstrated clinically relevant disease (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stages 2 or higher). These data are remarkably consistent with the published literature from other countries. A recent meta-analysis of all population-based prevalence studies across the world reported a pooled COPD prevalence of 9.2% (5.5% had GOLD stages 2 or higher COPD severity) (6). There are, however, some interesting and notable differences between Zhong and colleagues' study and the published studies to date. First, dissimilar to the meta-analysis, Zhong and colleagues' study found that rural compared with urban residents had a higher prevalence of COPD (9 vs. 8%). The exact reasons for this discrepancy are unclear, although there are several possibilities. Although China has experienced remarkable modernization over the past two decades, in many rural areas residents continue to use wood, charcoal, or coal for fuel, leading to significant biomass exposure, especially in women, who perform most of the cooking duties. Biomass exposure is an established risk factor for obstructive airway disease and reduced lung function (7). In addition, rural compared with urban residents in Zhong and coworkers' study were older and had greater tobacco exposure, which may have further increased their risk of COPD (5). Second, nearly 9% of the cohort had a "restrictive" defect on spirometry, defined as FEV1 less than 80% with a normal FEV1 to FVC ratio. The underlying pathobiology of these restrictive defects is uncertain. However, such individuals are at increased risk of morbidity and mortality from COPD, similar to those with obstructive airway disease (8). If one combines both the "restrictive" and "obstructive" disorders together, the overall prevalence of "lung disease" in China may be closer to 17% (8% for obstructive disease and 9% for restrictive disease). Although the burden of lung disease in China appears to be enormous, the tragic irony is that it is grossly underdiagnosed (and hence largely ignored). In Zhong and colleagues' study, fewer than 7% of subjects with COPD had been previously tested with spirometry, although two-thirds of them had symptoms suggestive of COPD (5). Even among subjects with GOLD stages 3 and 4 disease, fewer than 10% had ever received spirometry. These data are alarming because the assessment of airflow is absolutely essential in the proper diagnosis and management of COPD (9). The gross underutilization of spirometry represents a "Great Wall," a huge barrier to good care for patients with COPD in China. COPD is a highly preventable and treatable condition but only when it is properly diagnosed (9). The findings by Zhong and colleagues are not only a sobering reminder of the great challenges of integrating spirometry into the day-to-day practice of clinicians but also a call to develop novel and more acceptable noninvasive intermediate biomarkers (e.g., blood) that can complement (and perhaps even supplant) spirometry in the evaluation and management of patients with COPD in China and elsewhere. Perhaps then, the "Great Wall" in COPD care can be broken down and we can get on with properly managing and treating patients with COPD in hopes of curbing the epidemic of COPD in China and around the world. FOOTNOTES Conflict of Interest Statement: D.D.S. has received honoraria for speaking engagements from AstraZeneca (AZ) in 2004 ($3,000) and in 2005 ($11,000), and from GlaxoSmithKline (GSK) in 2004 ($8,000), 2005 ($6,500), 2006 ($10,000), and 2007 ($10,000); he has also received unrestricted research funding as either the principal investigator or co-principal investigator from GSK in 2004 for $1,500,000 and in 2006 for $200,000; he has also received $3,500 from GSK for consultancy work in 2004 and $1,500 in 2006. W.C.T. received unrestricted educational grants from AZ, Boehringer Ingelheim, and GSK for the study of prevalence of COPD. REFERENCES
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