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Background: Respiratory infections in early life are an identified risk factor for asthma. We hypothesized that infection-prevention measures during the coronavirus disease 2019 (COVID-19) pandemic influenced the risk of respiratory morbidity and aeroallergen sensitization in early childhood. Objective: We compared respiratory morbidity and aeroallergen sensitization in children born before and during the pandemic. Methods: We compared a COVID-19 category (exposed children; n = 1661) to a pre–COVID-19 category (nonexposed children; n = 1676) by using data from the prospective population-based NorthPop Birth Cohort study in Sweden. Data on respiratory morbidity and concomitant medication were retrieved from national registers. Prospectively collected data on respiratory morbidity using web-based questionnaires at 9 and 18 months of age were applied. At age 18 months, serum IgE levels to aeroallergens were determined (n = 1702). Results: The risk of developing any respiratory tract infection (adjusted odds ratio [aOR] = 0.33 [95% CI, 0.26-0.42]), bronchitis (aOR = 0.50 [95% CI, 0.27-0.95]) and croup (aOR = 0.59 [95% CI, 0.37-0.94]) were decreased in the COVID-19 category. The risk of wheeze in the first 9 months was lower in the COVID-19 category (aOR = 0.70 [95% CI, 0.55-0.89]). There were also fewer prescriptions of antibiotics in the COVID-19 category. The prevalence of aeroallergen sensitization was similar between categories. Conclusion: Children born during the COVID-19 pandemic demonstrated significantly decreased risks of respiratory infections and prescribed antibiotics until 18 months of age compared to children born before the COVID-19 pandemic. Whether this will affect the risk of developing asthma in childhood is being followed.

Importance: A diagnosis of bacterial meningitis in childhood can lead to permanent neurological disabilities. Few studies have examined long-term consequences for work ability in adulthood.

Objective: To compare earnings, work loss, and educational attainment between adults diagnosed with bacterial meningitis in childhood and population comparators.

Design, Setting, and Participants: This nationwide registry-based matched cohort study included individuals in Sweden diagnosed with bacterial meningitis in childhood (aged <18 years) from January 1, 1987, to December 31, 2019, and general population comparators matched 1:9 on age, sex, and place of residence. Follow-up was completed December 31, 2020. Data were analyzed from February 7 to September 12, 2023.

Exposure: A diagnosis of bacterial meningitis in childhood recorded in the National Patient Register.

Main Outcomes and Measures: Annual taxable earnings (in 2020 US dollars), work loss (sum of sick leave and disability insurance), and educational attainment.

Results: The cohort included 2534 individuals diagnosed with bacterial meningitis in childhood (mean [SD] age at diagnosis, 4.7 [5.3] years) and 22 806 comparators (13 510 [53.3%] male). Among those with childhood bacterial meningitis, 812 (32.0%) were diagnosed at younger than 1 year and 1351 (53.3%) were male. From 18 to 34 years of age, those with childhood meningitis had lower adjusted earnings relative to comparators and higher adjusted work loss. When pooling observations for individuals 28 years or older, the annual mean reduction in earnings was -$1295 (95% CI, -$2587 to -$4), representing a 4.0% (95% CI, 0%-8.0%) reduction relative to comparators, and the annual increase in work loss was 13.5 (95% CI, 8.6-18.5) days. There was a larger reduction in earnings for those with childhood meningitis relative to comparators with pneumococcal (Streptococcus pneumoniae) vs meningococcal (Neisseria meningitidis) meningitis. For work loss, there was a difference among all 3 major causes of meningitis, with the largest increase for pneumococcal meningitis. Individuals diagnosed at a younger age (below the median) had lower earnings relative to comparators and higher work loss than individuals diagnosed at an older age (above the median). Fewer individuals with childhood meningitis relative to comparators had obtained a high school degree at age 30 years (adjusted odds ratio, 0.68 [95% CI, 0.56-0.81]).

Conclusions and Relevance: In this cohort study of adults diagnosed with bacterial meningitis in childhood, findings suggest that work ability decreases relative to population comparators, with lower earnings and higher work loss, especially among adults diagnosed with pneumococcal meningitis or diagnosed at a young age, with long-lasting costs for the individual patient and society at large.

Aim: The burden of respiratory disease is great among children. This study aimed to examine the temporal relationship between hospitalisation for respiratory syncytial virus (RSV) and bacterial pneumonia.

Methods: A Swedish population-based cohort was created by combining data from the Swedish Medical Birth Register, the National Inpatient Register, the Cause of Death Register, the Total Population Register, and the Longitudinal Integration Database for Health Insurance and Labour Market Studies. Children born between 1998 and 2015 were included and followed for 2 years. We examined the temporal relationship between RSV hospitalisation and bacterial pneumonia using piecewise exponential models.

Results: The final cohort comprised 1 641 747 children, 48.5% were females. There were 23 632 RSV and 4722 bacterial pneumonia hospitalisations, with mean age of 137.8 and 424.2 days, respectively. RSV hospitalisation was associated with bacterial pneumonia with an adjusted incidence rate ratio (aIRR) of 3.18. The risk was highest in the first month after RSV hospitalisation, aIRR 11.19. The risk of bacterial pneumonia was elevated for 4 months after RSV hospitalisation and before RSV hospitalisation.

Conclusion: We found an increased risk for bacterial pneumonia hospitalisation in children hospitalised for RSV both before and after RSV hospitalisation, indicating a bidirectional relationship.

IMPORTANCE: Few studies have examined the incidence of long-term disabilities due to bacterial meningitis in childhood with extended follow-up time and a nationwide cohort.

OBJECTIVE: To describe the long-term risks of disabilities following a childhood diagnosis of bacterial meningitis in Sweden.

DESIGN, SETTING, AND PARTICIPANTS: This nationwide retrospective registry-based cohort study included individuals diagnosed with bacterial meningitis (younger than 18 years) and general population controls matched (1:9) by age, sex, and place of residence. Data were retrieved from the Swedish National Patient Register from January 1, 1987, to December 31, 2021. Data were analyzed from July 13, 2022, to November 30, 2023.

EXPOSURE: A diagnosis of bacterial meningitis in childhood recorded in the National Patient Register between 1987 and 2021.

MAIN OUTCOMES AND MEASURES: Cumulative incidence of 7 disabilities (cognitive disabilities, seizures, hearing loss, motor function disorders, visual disturbances, behavioral and emotional disorders, and intracranial structural injuries) after bacterial meningitis in childhood.

RESULTS: The cohort included 3623 individuals diagnosed with bacterial meningitis during childhood and 32 607 controls from the general population (median age at diagnosis, 1.5 [IQR, 0.4-6.2] years; 44.2% female and 55.8% male, median follow-up time, 23.7 [IQR, 12.2-30.4] years). Individuals diagnosed with bacterial meningitis had higher cumulative incidence of all 7 disabilities, and 1052 (29.0%) had at least 1 disability. The highest absolute risk of disabilities was found for behavioral and emotional disorders, hearing loss, and visual disturbances. The estimated adjusted hazard ratios (HRs) showed a significant increased relative risk for cases compared with controls for all 7 disabilities, with the largest adjusted HRs for intracranial structural injuries (26.04 [95% CI, 15.50-43.74]), hearing loss (7.90 [95% CI, 6.68-9.33]), and motor function disorders (4.65 [95% CI, 3.72-5.80]). The adjusted HRs for cognitive disabilities, seizures, hearing loss, and motor function disorders were significantly higher for Streptococcus pneumoniae infection (eg, 7.89 [95% CI, 5.18-12.02] for seizure) compared with Haemophilus influenzae infection (2.46 [95% CI, 1.63-3.70]) or Neisseria meningitidis infection (1.38 [95% CI, 0.65-2.93]). The adjusted HRs for cognitive disabilities, seizures, behavioral and emotional disorders, and intracranial structural injuries were significantly higher for children diagnosed with bacterial meningitis at an age below the median.

CONCLUSIONS AND RELEVANCE: The findings of this cohort study of individuals diagnosed with bacterial meningitis during childhood suggest that exposed individuals may have had an increased risk for long-term disabilities (particularly when diagnosed with pneumococcal meningitis or when diagnosed at a young age), highlighting the need to detect disabilities among surviving children.

Background: Social-emotional difficulties in early childhood are associated with a range of outcomes across the life course and are related to socioeconomic factors. The aim of this study was to examine intersectional inequalities in social-emotional problems in preschool children relating to their parents’ income, education and country of birth in addition to investigating the public health implications.

Methods: This population-based study with a repeated cross-sectional design in the Västerbotten County of Sweden used the Ages and Stages Questionnaires: Social-Emotional (ASQ:SE) for children aged 3 in child health care services over the years of 2014-2018 and socio-economic information from national population registers. The effective sample of 8,823 individuals was analyzed using additive binomial regression in combination with an analysis of individual heterogeneity and discriminatory accuracy (AIHDA) approach to estimate risk differences for social-emotional problems across 27 intersectional groups and discriminatory accuracy.

Results: Average risk differences generally increased in the groups where multiple dimensions of social inequality intersected, with risk differences as high as 18% (95% CI 8 to 28%) and 25% (95% CI 14 to 37%) compared to the most advantaged category. The discriminatory accuracy of all three included regression models was estimated as moderate, but improved in a slight but statistically significant way with the addition of social inequalities.

Conclusions: This study increases our understanding of intersectional and social inequalities in social-emotional problems in preschool children. It supports the need for universal public health policies in addition to policies targeting more vulnerable groups when addressing this issue, consistent with the concept of proportionate universalism. An intersectional research perspective including discriminatory accuracy could increase our knowledge of health inequities and improve public health effectiveness.

Background: It is well known that socially deprived children are more likely to be hospitalised for infections. Less is known about how different social disadvantages interact. Therefore, we examine intersectional inequalities in overall, upper respiratory, lower respiratory, enteric and genitourinary infections in the first 5 years of life.

Methods: We conducted a population-based retrospective cohort study of Swedish children born between 1998 and 2015. Inequalities were examined using analysis of individual heterogeneity and discriminatory accuracy as the analytical framework. A variable with 60 intersectional strata was created by combining information on maternal education, household income, sex/gender and maternal migration status. We estimated the incidence rates of infectious disease hospitalisation for each intersectional strata and the associations between intersectional strata and infectious disease hospitalisations using logistic regression models. We furthermore quantified the discriminatory ability of the intersectional strata with respect to infectious disease hospitalisation.

Results: The study included 1785 588 children and 318 080 hospital admissions. The highest overall incidence of hospitalisations for infections was found in boys born to low-educated mothers who lived in families with the lowest household income. The overall incidence of infections was unrelated to household income in children born to highly educated mothers. The ability of the intersectional strata to discriminate between children with and without infections was poor.

Conclusion: We found that inequalities in paediatric infectious diseases were shaped by the intersections of different social disadvantages. These inequalities should be addressed by public health policies that reach all children.

Background: Randomized controlled trials have demonstrated that early introduction of allergenic foods, such as peanut and egg, can reduce food allergy in high-risk children. Many international guidelines recommend introduction of allergenic foods in the first year of life, and accordingly, the Swedish National Food agency released updated guidelines in June 2019.

Objective: Our aim was to examine whether the age at introduction and consumption frequency of allergenic foods have changed since release of the revised national guidelines on the introduction of solid foods in Sweden.

Methods: Children born between June 2016 and December 2018 (n = 1925) were compared with children born between June 2019 and April 2021 (n = 1761) by using data from the NorthPop Birth Cohort study. Data on food introduction, eczema, and food allergy were prospectively collected until age 18 months by using web-based questionnaires. IgE sensitization was assessed at 18 age months.

Results: The proportion of participants who had been introduced to egg, legume, soy products, peanut, almond, and cashew nut during the first year of life increased after implementation of the revised national guidelines. The most significant changes were seen for legume (from 55.2% to 69.8% [adjusted odds ratio = 1.90 (95% CI = 1.62-2.24)] and peanut (from 29.2% to 43.2% adjusted odds ratio = 1.87 (95% CI = 1.55-2.24)]); consumption frequency had also increased. No differences in the prevalence of eczema, food allergy, or sensitization to the foods of interest were found.

Conclusion: Since release of the revised guidelines, infants in the general population are introduced to and consume a variety of allergenic foods earlier and more frequently; however, early manifestations of allergic disease have remained unchanged.

Aim: We evaluated the effect on body mass index standard deviation score (BMI-SDS) of a combined treatment (Web-COP) for children with obesity, including a web-based component targeting their parents.

Methods: This randomised controlled trial recruited children 5–12 years of age with obesity (International Obesity Task Force BMI [IOTF-BMI] ≥30 kg/m2) from school health care and outpatient paediatric clinics in in Northern Sweden from 1 June 2019 to 21 June 2020. The children were randomised to Web-COP, an intervention with group sessions and a 12-week web-based component, or standard care. The primary outcome was the change in IOTF BMI-SDS after 6 months.

Results: In total, 75 children (33 girls), mean age 9.5 years, were randomised, and 65/75 (87%) children and their parents completed the study, 35/39 (90%) in the Web-COP intervention and 30/36 (83%) in the standard care group. BMI-SDS at 6 months was changed from 3.08 to 2.81 in the intervention group compared to an increase from 3.07 to 3.16 in the standard care group, representing a significant difference between groups (p < 0.001). In the intervention group, 14/30 (47%) reduced their BMI-SDS ≥0.25, compared to none in the standard care group.

Conclusion: The parent-focused intervention significantly improved BMI-SDS in children with obesity as compared to children in standard care.

Objective: To examine how the effect of disadvantaged socioeconomic circumstances on the risk of paediatric infections is mediated by pregnancy smoking, excess weight during pregnancy and breast feeding in children under 5 years of age.

Design: A population-level, retrospective cohort study. The Swedish Medical Birth Register was combined with the National Patient Register, the longitudinal integration database for health insurance and labour market studies, the Cause of Death Register and a local register held by the Child Health Care Unit in Uppsala Region.

Setting: Uppsala Region, Sweden.

Patients: 63 216 term and post-term singletons born to women who resided in Uppsala Region, Sweden between 1997 and 2015.

Main outcome measures: Number of hospital admissions for infectious diseases. Secondary outcomes were the number of hospitalisations for respiratory and enteric infections, respectively.

Results: The effect of disadvantaged socioeconomic circumstances, that is, low maternal education on the overall risk of paediatric infections was mediated to a considerable (33%-64%) proportion by pregnancy smoking, excess weight during pregnancy and breast feeding.

Conclusions: Pregnancy smoking, excess weight during pregnancy and breast feeding mediate a considerable proportion of the association between deprived socioeconomic circumstances and paediatric infectious diseases. Therefore, inequalities in paediatric infectious diseases may be reduced by public health policies addressing these health-related behaviours.