Prevalence and risk factors of asthma in mainland China: The CARE study

Background: There are limited population based data on the prevalence of asthma in China. The China Asthma and Risk factors Epidemiologic (CARE) survey was designed to understand the prevalence and risk factors for asthma in mainland China. Objectives: The CARE survey aims to demonstrate the prevalence and risk factors of asthma in mainland China among adolescents (age > 14 years) and adults. Methods: The survey was performed between February 2010 and August 2012 in eight provinces/cities of seven areas in mainland China. The inhabitants (age, > 14 years) recruited in this survey were through multi-stage cluster random sampling. Asthma diagnosis was based on medical history and lung function tests. Multivariable logistic regression was used to analyzed the risk factors for asthma. Results: The study included 164 215 subjects (men, 79 692 [48.53%]; women, 84 523 [51.47%]). 2034 (1.24%) were asthmatic patients. Among all asthmatic patients, 521 (25.61%) were newly diagnosed. Univariable regression analysis showed that risk factors for asthma included smoking, first-degree relatives with asthma, allergic rhinitis, chronic bronchitis, COPD, pollinosis, allergic pneumonia, concomitant allergic diseases, BMI and raising pets. Multivariable logistic regression indicated that asthma risk factors included women, age stratification, smoking, first-degree relatives suffering from asthma or pollinosis, combined with allergic rhinitis, eczema or GERD. Conclusions: We speculated that the prevalence of asthma is increasing in mainland China among individuals aged > 14 years in the past 10 years. A number of risk factors were identified. The risk factors of asthma would be further elucidated in our future work. Clinical implications: Our CARE study highlights that asthma epidemic in mainland China should be paid more attention.