The prevalence of asthma in Iranian adults: The first national survey and the most recent updates.

Background: The worldwide increase in the prevalence of asthma has made it a major public-health concern. We aimed to identify the prevalence of asthma and asthma symptoms in adults living in urban and rural areas of Iran as a populated country with about 80 millions of residents.

Methods: This cross-sectional study was conducted to estimate the prevalence of asthma in adults between 20 and 44 years old in all provinces of Iran. Data were collected by personal interview via a standardized questionnaire [European Community Respiratory Health Survey (ECRHS)] between November 2015 and February 2016.

Results: A total of 24 344 individuals were enrolled. The prevalence of asthma was 8.9% [95% confidence interval (CI): 8.5-9.3]. The most common asthma symptoms were wheezing (14.2%, n = 3465), nocturnal cough (13.3%, n = 3234) and chest tightness (11.3%, n = 2760). Additionally, the prevalence of current asthma (taking asthma medications or asthma attack) was estimated to be 4.7% (n = 1155). Asthma was significantly more prevalent in males compared to females (P = .002), while no significant relationship was detected between gender and asthma after adjusted analysis with other variables. The prevalence of asthma was significantly higher in older participants (P < .001) and individuals with low educational level (P < .001). Interestingly, there was no significant relationship between asthma and area of residency (P = .8).

Conclusions: The prevalence of asthma in Iran was similar to other Asian and European countries. However, repeated national surveys are required to determine the trend of asthma prevalence in Iran in comparison to other countries.