Global, regional, and national burden of asthma and risk factors from 1990 to 2021: Global Burden of Disease study 2021

<b>Background:</b> Asthma remains a substantial global health challenge, whereas epidemiologic data beyond 2019, particularly in the post-coronavirus disease 2019 era, are limited. This study aimed to provide a comprehensive view of the temporal and spatial trend of asthma burden and its attributable risk factors from 1990 to 2021. <b>Methods:</b> By using data from the Global Burden of Disease 2021 study, we analyzed the global, regional, and national trends in asthma incidence, deaths, and disability-adjusted life years (DALY) from 1990 to 2021. The smoothing splines models were applied to assess the relationship between the asthma burden and the sociodemographic index (SDI). An age-period-cohort (APC) model was used to study the detailed trend, and risk factor contributions were quantified. <b>Results:</b> Globally, asthma showed a favorable downward trend of incidence, deaths, and DALYs from 1990 to 2021. A negative correlation was found between SDI and the asthma burden. The APC analysis showed a relative high incidence rate in childhood and a high death rate in the elderly. A favorable period and cohort effect was observed. High body mass index has surpassed smoking as the leading risk factor for asthma-related deaths and DALYs. <b>Conclusion:</b> Although the asthma burden declined from 1990 to 2021, the overall issue with national and regional discrepancies persists. The shift in the leading risk factor necessitates targeted public health policies and interventions to effectively mitigate its impact.