RESUMO
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is set to become the third most frequent cause of death and also the third largest cause of global morbidity by 2020. In China, where the population is aging rapidly, COPD has become one of the leading causes of disability and a large economic burden. An epidemiological assessment of the COPD in China is required, with a focus on the number of cases living with disease, main determinants of the disease and time trends. METHODS: We systematically searched large Chinese bibliographic databases and English databases to identify spirometry-based epidemiological studies of the prevalence of COPD in China diagnosed according to GOLD criteria. We estimated age- and gender-specific prevalence of COPD using a multilevel mixed-effect logistic regression. We also presented the time trends of COPD between 1990 and 2010 by age, gender and setting (urban vs rural). FINDINGS: In 1990, the prevalence of COPD ranged from 0.49% (95% CI = 0.29-0.85) in <20 years group to 20.95% (95% CI = 14.04-27.04) in> = 80 years group, and the crude prevalence for China was 2.70% (95% CI = 1.86-3.51). In 2010, the prevalence in <20 years was 0.55% (95% CI = 0.37-1.04) and in> = 80 years was 22.89% (95% CI = 18.13-28.96), with the crude prevalence for China of 3.84% (95% CI = 3.30-4.77). The COPD prevalence in males was about two-fold higher than in females, and it increased with increasing age. Between 1990-2010, the total number of Chinese people living with COPD increased by 66.73%, from 30.90 million (95% CI = 21.28-40.02) in 1990 to 51.52 million (95% CI = 44.26-63.93) in 2010. This increase was most striking in middle age, and greater in females than in males from 30 years up to 64 years. Our estimates, which used an independent approach to acquiring data and development of analytical methods, and were based on a more complete data set, are remarkably similar to those produced recently by the GBD 2013 collaboration, differing by only about 5% in the estimated number of COPD cases in 1990 and by 1% in 2010. CONCLUSIONS: COPD is a highly prevalent disease in China and its importance is growing steadily. The number of people living with COPD has increased substantially between 1990 and 2010. COPD is more frequent in males and in rural areas. Optimised primary and secondary prevention and treatment is urgently needed to counter this growing trend. Improved epidemiological studies will be required to assist development of more effective strategies of prevention and treatment of COPD in China in the next decade and beyond.