Abstract
Lower respiratory infections are a leading cause of morbidity and mortality around the world. The Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study 2016 provides an up-to-date analysis of the burden of lower respiratory infections in 195 countries. This study assesses cases, deaths, and etiologies spanning the past 26 years and shows how the burden of lower respiratory infection has changed in people of all ages.
Methods
We used three separate modeling strategies for lower respiratory infections in GBD 2016: a Bayesian hierarchical ensemble modeling platform (Cause of Death Ensemble model), which uses vital registration, verbal autopsy data, and surveillance system data to predict mortality due to lower respiratory infections; a compartmental meta-regression tool (DisMod-MR), which uses scientific literature, population representative surveys, and health care data to predict incidence, prevalence, and mortality; and modeling of counterfactual estimates of the population attributable fraction of lower respiratory infection episodes due to Streptococcus pneumoniae, Haemophilus influenzae type b, influenza, and respiratory syncytial virus. We calculated each modeled estimate for each age, sex, year, and location. We modeled the exposure level in a population for a given risk factor using DisMod-MR and a spatiotemporal Gaussian process regression, and assessed the effectiveness of targeted interventions for each risk factor in children younger than 5 years. We also did a decomposition analysis of the change in LRI deaths from 2000 to 2016 using the risk factors associated with LRI in GBD 2016.
Findings
In 2016, lower respiratory infections caused 652,572 deaths (95% uncertainty interval [UI] 586,475–720,612) in children younger than 5 years (under-5s), 1,080,958 deaths (943,749–1,170,638) in adults older than 70 years, and 2,377,697 deaths (2,145,584–2,512,809) in people of all ages, worldwide. Streptococcus pneumoniae was the leading cause of lower respiratory infection morbidity and mortality globally, contributing to more deaths than all other etiologies combined in 2016 (1,189,937 deaths, 95% UI 690,445–1,770,660). Childhood wasting remains the leading risk factor for lower respiratory infection mortality among children younger than 5 years, responsible for 61.4% of lower respiratory infection deaths in 2016 (95% UI 45.7–69.6). Interventions to improve wasting, household air pollution, ambient particulate matter pollution, and expanded antibiotic use could avert one under-5 death due to lower respiratory infection for every 4,000 children treated in the countries with the highest lower respiratory infection burden.
Interpretation
Our findings show substantial progress in the reduction of lower respiratory infection burden, but this progress has not been equal across locations, has been driven by decreases in several primary risk factors, and might require more effort among elderly adults. By highlighting regions and populations with the highest burden, and the risk factors that could have the greatest effect, funders, policymakers, and program implementers can more effectively reduce lower respiratory infections among the world’s most susceptible populations.