Risk factors for admission to the pediatric critical care unit among children hospitalized with COVID-19 in France

Abstract

Background: COVID-19 infection is less severe among children than among adults; however, some patients require hospitalization and even critical care. Using data from the French national medico-administrative database, we estimated the risk factors for critical care unit (CCU) admissions among pediatric COVID-19 hospitalizations, the number and characteristics of the cases during the successive waves from January 2020 to August 2021 and described death cases.

Methods: We included all children (age < 18) hospitalized with COVID-19 between January 1st, 2020, and August 31st, 2021. Follow-up was until September 30th, 2021 (discharge or death). Contiguous hospital stays were gathered in "care sequences." Four epidemic waves were considered (cut off dates: August 11th 2020, January 1st 2021, and July 4th 2021). We excluded asymptomatic COVID-19 cases, post-COVID-19 diseases, and 1-day-long sequences (except death cases). Risk factors for CCU admission were assessed with a univariable and a multivariable logistic regression model in the entire sample and stratified by age, whether younger than 2.

Results: We included 7,485 patients, of whom 1988 (26.6%) were admitted to the CCU. Risk factors for admission to the CCU were being younger than 7 days [OR: 3.71 95% CI (2.56-5.39)], being between 2 and 9 years old [1.19 (1.00-1.41)], pediatric multisystem inflammatory syndrome (PIMS) [7.17 (5.97-8.6)] and respiratory forms [1.26 (1.12-1.41)], and having at least one underlying condition [2.66 (2.36-3.01)]. Among hospitalized children younger than 2 years old, prematurity was a risk factor for CCU admission [1.89 (1.47-2.43)]. The CCU admission rate gradually decreased over the waves (from 31.0 to 17.8%). There were 32 (0.4%) deaths, of which the median age was 6 years (IQR: 177 days-15.5 years).

Conclusion: Some children need to be more particularly protected from a severe evolution: newborns younger than 7 days old, children aged from 2 to 13 years who are more at risk of PIMS forms and patients with at least one underlying medical condition.

Keywords: COVID-19; SARS-CoV-2; children; critical care; hospitalization.

FIGURE 1

Study patient selection flow chart.

FIGURE 2

Number of COVID-19 hospitalizations and of the PIMS and respiratory forms according to the age and gender of the patient. The bars give the number of COVID-19 hospitalizations for the males (blue) and the females (pink) separately. The lines give the proportion of the PIMS (red dotted line) and respiratory (black plain line) forms among the hospitalizations.

FIGURE 3

Forest plot showing the odds ratio using Univariable (Uni) and Multivariable (Multi) Logistic regression analysis for CCU admission for all children. CCU, critical care unit; PIMS, pediatric multisystem inflammatory syndrome; OR, Odds ratio; 95% CI, 95% confidence interval.

FIGURE 4

Forest plot showing the odds ratio using univariable (Uni) and multivariable (Multi) logistic regression analysis for CCU admission for children younger than 2 years old. CCU, critical care unit; PIMS, pediatric multisystem inflammatory syndrome; OR, odds ratio; 95% CI, 95% confidence interval. *Excluding asthma; **including cancers; ^†excluding diabetes; ^‡renal disease, hepatic and gastric disease, and diabetes.

FIGURE 5

Forest plot showing the odds ratio using univariable (Uni) and multivariable (Multi) logistic regression analysis for CCU admission for children older than 2 years old. CCU, critical care unit; PIMS, pediatric multisystem inflammatory syndrome; OR, odds ratio; 95% CI, 95% confidence interval. *Excluding asthma; ^†including cancers; ^‡excluding diabetes.

FIGURE 6

Number of pediatric COVID-19 hospitalizations by month and percentage of COVID-19 hospitalizations in critical care units in France from February 2020 to August 2021. The bars give the number of COVID-19 hospitalizations per month. The black plain line gives the percentage of CCU admissions among the COVID-19 hospitalizations.