Trend and Burden of Suboptimal Breastfeeding in Children Under Five Years of Age in 1990-2021: A Systematic Analysis for the Global Burden of Disease Study 2021.

: Breastfeeding is a cost-effective early child health intervention that has been identified as a protective factor against adverse child health outcomes. However, as estimated by previous epidemiological studies, the prevalence of breastfeeding in most countries around the world is below the recommended levels established by the World Health Organization. This study aims to assess the changes in suboptimal breastfeeding mortality, disability-adjusted life years (DALYs), and years lost to disabilities (YLDs) on a global, regional, and national level from 1990 to 2021. : Data regarding suboptimal breastfeeding in children under 5 years of age from 1990 to 2021 were extracted from the Global Health Data Exchange query tool. Data from 204 countries and territories countries were classified into 5 regions based on the sociodemographic index (SDI) and 21 Global Burden of Disease (GBD) regions according to geographical contiguity. The average annual percentage change (AAPC) was calculated to assess changes in the trends of suboptimal breastfeeding DALYs, YLDs, and mortality in the past 30 years. : Countries with high-middle (AAPC = -0.94, 95% CI = -0.95 to -0.93) SDI scores had the greatest degree of improvement in both suboptimal breastfeeding mortality from 28,043.47 to 1128.24 and disease burden from 43,202.94 to 4428.47, while countries with high (AAPC = -0.83, 95% CI = -0.86 to -0.81) and low SDI (AAPC = -0.63, 95% CI = -0.71 to -0.55) scores showed the least improvement from 16,775.75 to 5930.56 and 49,522.23 to 32,881.08, respectively. : Significant global improvements in suboptimal breastfeeding mortality and morbidity have occurred in the last 30 years. However, the extent of improvement differs significantly across nations, while some countries also showed no improvements or increased suboptimal breastfeeding mortality and disease burden. Nation-specific policies that account for cultural practices and economic conditions are required to target vulnerable mothers that are unable to achieve optimal breastfeeding.