Epidemiology of childhood asthma in mainland China (1988-2014): A meta-analysis

Background: After the promotion of the two-child policy in recent years, the population of children in mainland China was bound to have a rapid growth, which would bring great challenges to public health. A number of cross-sectional studies on the epidemic of childhood asthma in mainland China were recently conducted, and varied prevalences were reported. Thus, knowing the epidemiology of childhood asthma in mainland China is of great necessity. Objective: Our study aimed to summarize the pooled prevalence of childhood asthma in mainland China and its time trend, gender difference, regional distribution, and age structure. Methods: Studies that reported the prevalence of childhood asthma in mainland China were identified via a systematic data base search through July 1, 2016. Meta-analysis was used to estimate the prevalence of childhood asthma and its subgroups, including gender, age groups, years, and regions. The regional distribution of the prevalence was set by province with the help of a geographic mapping software. The autoregressive integrated moving average model was used to predict the current prevalence of asthma. Results: A total of 117 studies published from 1988 to 2014 in mainland China with a total sample size of 2,678,696 were included. The overall current prevalence and lifetime prevalence of childhood asthma was 2.112% (95% confidence interval [CI], 1.977-2.247%) and 2.502% (95% CI, 2.166 -2.838%), respectively. The difference of the prevalences between male and female patients was significant: odds ratio 1.54 (95% CI, 1.47-1.62) for the current prevalence and odds ratio 1.61 (95% CI, 1.47-1.77) for the lifetime prevalence. Conclusion: The prevalence of childhood asthma in mainland China was low but has been increasing remarkably since 1998. Boys are more likely to have asthma throughout most of their childhood. Preschoolers (3-6 years old) showed a higher prevalence than the other age groups. The current prevalence of childhood asthma probably increased slightly from 2017 to 2019.