The Childhood Acute Illness and Nutrition (CHAIN) network nested case-cohort study protocol: a multi-omics approach to understanding mortality among children in sub-Saharan Africa and South Asia

<ns4:p> <ns4:bold>Introduction</ns4:bold> : Many acutely ill children in low- and middle-income settings have a high risk of mortality both during and after hospitalisation despite guideline-based care. Understanding the biological mechanisms underpinning mortality may suggest optimal pathways to target for interventions to further reduce mortality. The Childhood Acute Illness and Nutrition (CHAIN) Network ( <ns4:ext-link xmlns:ns5="http://www.w3.org/1999/xlink" ext-link-type="uri" ns5:href="http://www.chainnnetwork.org">www.chainnnetwork.org</ns4:ext-link> ) Nested Case-Cohort Study (CNCC) aims to investigate biological mechanisms leading to inpatient and post-discharge mortality through an integrated multi-omic approach. </ns4:p> <ns4:p> <ns4:bold>Methods and analysis</ns4:bold> ; The CNCC comprises a subset of participants from the CHAIN cohort (1278/3101 hospitalised participants, including 350 children who died and 658 survivors, and 270/1140 well community children of similar age and household location) from nine sites…