Hospitalizations for infections by age and sex: register-based study of Danish children 1977–2014

Abstract

Background: Infectious diseases are a major cause of hospitalisations in children and there is increasing interest in sex differences in immunity during childhood. Therefore, we examined hospital admission rates for infectious diseases in Danish children by age and sex. Method:Register-based cohort study of all Danish residents aged 0-14 years from 1977-2014. We examined total admission rate for infections and rates of admission by types of infection.Results: This study included 3,689,999 children and 1,080,750 admissions for infections.The admission rates peaked at age 0 months (boys, 197.9 admissions per 1000 person-years; girls, 160.9) and age 11 months (boys, 155.5; girls, 113.9). The male-female ratio of admissions was 1.25 for children aged 0-14 years, but varied by age and type of infection.Boys had the highest admission rate for any infection until 9 years of age after which girls had a higher rate. Boys had higher admission rates for gastrointestinal infections and lower respiratory tract infections than girls at all ages. The admission rates for upper respiratory tract infections and "Other infections" for girls were higher than the rates for boys at age 10 and 4 years, respectively. Conclusion:Overall, boys had around 25% higher admission rates for infections than girls, with some variation according to age and type of infection.

Hospital Contacts for Infectious Diseases Among Children in Denmark, Finland, Norway, and Sweden, 2008–2017

“… 35 In addition, sex hormones affect the immune system differently at different ages, 35 which has been proposed to contribute to the divergent sex differences in infections according to age. 1 This aligns with our observation that boys had higher rates of inpatient contacts with overnight stays until approximately 5 years of age and lower rates after 13 years of age compared with girls.…”

“…In all countries, the highest rates were observed among young infants (up to three months of age). This may be a result of neonatal complications and hospitalisation of children born preterm with a higher risk of infections 33 but may also reflect secondary diagnoses among otherwise healthy new-borns (ie, eye infections) 1 as well as low thresholds for admitting the youngest children with otherwise uncomplicated infections overnight.…”

“…Infectious diseases are common in childhood. 1 , 2 Minimizing the burden of paediatric infectious diseases is of public health interest 3 with national preventive strategies, eg, vaccination programs in place to fulfil this aim. 4 In high-income countries, measures of hospital care utilisation for infections are often used to ascertain the burden of paediatric infectious diseases.…”

“…The Nordic countries Denmark, Finland, Norway, and Sweden have many similarities, including the welfare state model promoting universal tax-funded healthcare for all. 5 , 6 Previous Nordic studies describing paediatric hospitalisations for infections are limited to single country investigations, 1 , 7–16 and are often restricted to specific types of infections, 7–11 , 13 , 14 , 16 hampering cross country comparison.…”

Consequences of COVID-19–related lockdowns and reopenings on emergency hospitalizations in pediatric patients in Denmark during 2020–2021

“…There was also a clear trend of seasonal variations in RTIs and pulmonary diseases like asthma and AB event rates in pre-pandemic years. This is a well-known trend in Denmark as well as in other countries [ 4 – 7 , 17 , 18 ].…”