Geographic pattern of asthma prevalence in Brazilian adolescents: a systematic review with meta-analysis

This study aimed to verify the prevalence of asthma in Brazilian adolescents and its geographic pattern carried through a systematic review and meta-analysis.

A survey of databases (Pubmed, Chocrane, LILACS, SCIELO and SCOPUS) was carried out, following the PRISMA statement, between the years 2013 and 2023 (PROSPERO-ID-CRD42023427988). Articles that presented a measure relative to the prevalence of asthma in adolescents were included. The methodological quality regarding risk of bias was assessed according to the approach proposed by the Joanna Brigg Institute.

Ten of a total of 3140 studies were included. Six studies were collected before 2015. The prevalence of active asthma, severe asthma, and diagnosed asthma were 18 %, 6 %, and 14 %, respectively. The studies were presented in large urban centers and capitals, had a high methodological quality, and showed high heterogeneity. Subgroup analysis was carried out, separating the cities according to the different regions of Brazil (north, northeast, center-west, south, and southeast). The northeast was the region with the lowest prevalence of active asthma (14 %, 95 % CI = 12-17 %, p < 0.001). There was no difference between regions in terms of diagnosed asthma and severity.

A high proportion of Brazilian adolescents reported having active asthma, with the northeast region having the lowest prevalence. Most of the studies were collected more than eight years ago and regard capitals and large urban centers. The high heterogeneity found demonstrates uncertainty in asthma prevalence in Brazil and highlights the need for clearer protocols addressing the multifactorial nature of the disease.