Epidemiology of Infection-Related Hospitalisations in High-Income Countries: An International Data Linkage Study

Abstract

Introduction Childhood infection is a leading cause of morbidity and mortality worldwide, however, the epidemiology of infection-related hospitalisations (IRH) across high-income countries is not well described. Population-level data are valuable resources for studying the epidemiology of severe infections. Objectives and Approach We used data from our multi-country total population-based cohort study to describe the patterns of IRH across six populations in five countries. Our cohort study contains birth and hospitalisation data on all singleton live births from 1996-2015 from Australia (New South Wales and Western Australia), Denmark, Norway, Scotland, and England. Children were classified as having an IRH if they had an inpatient hospital admission that incurred at least one primary or secondary infectious disease discharge ICD code, at least one day after the birth-related discharge date and if they were less than five years of age at discharge. IRH were classified as overall and by clinical group. Here we present interim analyses from Denmark and Scotland, n=1,593,008 (further results will be presented at the conference). Results More boys than girls had an IRH by 5 years of age (boys 26%, girls 21%). By 1 year, 12% of boys and 9% of girls experienced their first IRH, whereas between 1-5 years of age, 14% of boys and 12% of girls experienced their first IRH. Overall, 7% of children had >1 IRH. The majority of infections were lower and upper respiratory tract infections, followed by viral and gastrointestinal infections. Infection was commoner in the lowest socio-economic status groups. Conclusion / Implications IRH remains a leading cause of hospitalisation in preschool children. Understanding the epidemiology of IRH in high-income countries is important for targeting appropriate interventions and reducing disease burden.