Prevalence of asthma in iranian children: a meta-analysis and meta-regression

Asthma is the most prevalent chronic disease in childhood and has been growing globally over the last three decades. Studies in this regard indicate different and irrelevant results in Iran. Different prevalence of asthma has been reported in industrialized countries, prevalence of 25.9% in the United Kingdom, 12.8% in Spain and 31% in Australia. This study aimed to evaluate asthma in Iranian children through systematic review and meta-analysis.

This study was performed as a systematic review and meta-analysis from January 2001 to December 2018. Related articles to the reviewed subject were obtained through searches of Scopus, ScienceDirect, Magiran, SID, Medline (PubMed), and Google Scholar databases. Cross-sectional studies were selected for inclusion in the study and observational studies as well as review studies were excluded from the study. Searches on Google search engine and the inspection of sites related to the topic were also incorporated to examine the grays literature. Duplicate articles and articles that were similar and obtained from the same source were removed through the EndNote software. The total number of articles was 896. Subsequently, the number of articles and studies that met the requirements of the first stage was 274. Ultimately after the elimination of 236 irrelevant articles and the elimination of 5 articles in the secondary examination, eventually 33 articles were added to the final stage. By the I2 index, the heterogeneity of the studies was investigated and reported.

In a survey of 33 studies and 97205 participants in the age range of (3-18) years, the general prevalence of asthma in this study based on meta-analysis was 5.1% (CI95%: 4-6.5%). The highest prevalence of asthma was among children from Babol which was 19% (CI95%: 17.8% -20.3%) in 2014 and the lowest prevalence of asthma was among children from Isfahan with 0.7% of prevalence (CI95%: 0.5-1.1) in 2001. Also, with the increase of research years and overall sample size in each study, asthma in children shows increasing and decreasing levels, respectively; and the differences were statistically significant.

Based on what was reported in this study, the prevalence of asthma among Iranian children is lower compared to children of developed countries.