# Global to local burden and inequalty of low respiratory infections among children and adolescents across 953 locations

## TL;DR

This study examines how lower respiratory infections affect children and adolescents globally, revealing significant regional disparities and progress in reducing disease burden.

## Contribution

The study provides subnational resolution data on LRI burden across 953 locations, uncovering local inequalities masked in national-level estimates.

## Key findings

- From 1990 to 2021, adolescent LRI incidence decreased by 55.8%, and DALYs decreased by 76.7%.
- Mandera in Kenya and Sokoto in Nigeria had the highest LRI incidence and DALYs rates in 2021.
- Despite progress, 1.8 million adolescents worldwide still suffer from LRIs, with significant disparities in low-SDI regions.

## Abstract

Adolescent lower respiratory infections (LRIs) are one of the major public health problems worldwide. Utilizing data from Global Burden of Disease 2021 (GBD 2021), this study aimed to investigate the trends and distribution characteristics of the burden of LRIs among children and adolescents from global to local levels, as well as to assess inequalities in disease burden. Unlike previous GBD reports, our analysis provides unprecedented subnational resolution across 953 global locations, uncovering local inequalities often masked in national-level estimates.

We conducted an extensive analysis of the impact of LRIs across 953 global regions. This investigation included various metrics, including prevalence, incidence, mortality, disability-adjusted life years (DALYs), years of life lost (YLLs) and years lived with disability (YLDs). Additionally, we performed an inequality analysis and a frontier analysis pertinent to the sociodemographic index (SDI).

From 1990 to 2021, the incidence rate among adolescents decreased by 55.8%, and the DALYs rate decreased by 76.7%. Mortality rates decreased from 127.7 (95% uncertainty interval [UI]: 110.9 to 149.7) in 1980 to 21.2 (95% UI: 17.5 to 25.5) in 2021. In 2021, there were still 1.8 million adolescents worldwide suffering from LRIs. Among 652 local administrative regions, Mandera in Kenya had the highest incidence rate at 7,743.6 (95% UI: 6,876.8–8,715.6), and Sokoto in Nigeria had the highest DALYs rate at 16,663.3 (95% UI: 11,825.8–22,776.3). Since 1990, the global burden of LRIs among adolescents has significantly decreased, but regional disparities remain significant. From 1990 to 2021, the slope index of inequality (SII) for incidence rates and DALYs rates decreased by 56.8% and 81.5%, respectively, with higher disease burdens in low- and low- middle-SDI regions. In 2021, only 14.2% reached the incidence rate frontier level, and 15.2% reached the DALYs rate frontier level.

Substantial progress has been made in reducing the burden of LRIs, but the burden remains heavy, particularly in low- and low- middle SDI regions. Trend analysis provides scientific evidence for international aid and policy-making to address inequalities.

The online version contains supplementary material available at 10.1186/s12889-025-25757-8.