Prevalence and risk factors of asthma among adults in Songjiang District of Shanghai： a cross-sectional study

ObjectiveTo determine the prevalence and risk factors of asthma among adults.

MethodsA total of 37 670 adults aged 18 years and above was enrolled in Songjiang District， Shanghai using a multi-stage stratified sampling method between April 2016 and October 2017. Statistical analysis， such as t-test and Chi-square test， was performed to check the difference between the participants with asthma and non-asthma participants. Risk factors for asthma were examined by logistic regression analysis in all participants.

ResultsOverall， 36 698 subjects were enrolled in the study， in which 752 had asthma. The overall prevalence of asthma was determined to be 2.05%. The prevalence in females was 2.16%， and that in males was 1.88%， which didn’t achieve significance（P>0.05）. Compared to non-asthma participants， those with asthma were more likely to be older （［60.3±9.48］ years vs. ［56.29±11.31］ years）， widowed （6.91%>4.45%，P<0.05）， with educational level of primary school and below （58.64%>46.55%， P<0.01）， higher level of total cholesterol （TC） and low-density lipoprotein cholesterol （LDL-C） （P<0.05）， had more co-morbidities， such as hypertension （42.00%>15.00%，P<0.001）， chronic obstructive pulmonary disease （COPD） （6.25%>0.41%，P<0.001）， chronic bronchitis （51.33%>6.32%，P<0.001） and tuberculosis （2.66%>0.96%，P<0.05）， depression（2.13%>0.41%，P<0.05）， and Parkinson's disease （0.93%>0.39%，P<0.05）. Multivariable analysis showed that family history of asthma， history of hypertension， chronic bronchitis， COPD， depression and educational level of primary school and below were the risks factors associated with adult asthma （P<0.05）.

ConclusionPrevalence of adult asthma in Shanghai has increased in recent years. Targeted health education may be strengthened for improving adult awareness towards asthma and reducing the disease burden.