A comparison of health care use after severe COVID-19, respiratory syncytial virus, and influenza in children

Background: We aimed to explore whether children in hospital care with COVID-19 have increased post-discharge health care use when compared to children in hospital care with 1) RSV infection, and 2) other RTIs. Methods: In 34,214 children aged 1 month to 5 years who were registered with one or more hospital contacts with COVID-19 (N=128), RSV infection (N=4,009) or other RTIs (upper- and lower unspecified RTI as well as influenza) (N=34,457) (January 1st, 2017 to September 20th, 2021), we used a pre-post study design to investigate the individual all-cause primary and specialist health care use from 12 weeks prior to hospital admission, to 12 weeks after hospital discharge, stratified on infants (1-12 months) and toddlers (1-5 years). Findings: We found a slight increase in primary health care use in the first four weeks after discharge for children aged 1-12 months with COVID-19 when compared to children with RSV infection (0.064 percentage points, 95% CI 0.02-0.126, 0.52% relative increase). For children aged 1-5 years, COVID-19 discharge was associated with a 1-4 weeks increase in primary health care use when compared to children with RSV infection (0.068 percentage points, 95% CI 0.022-0.144, 0.53% relative increase) and other RTI (0.046 percentage points, 95% CI 0.002-0.091, 0.45% relative increase). For children aged 1-12 months in hospital care with COVID-19, we found a similar-magnitude-increase in post-discharge inpatient specialist care use, which lasted for 12 weeks. Interpretation: Our findings imply no severe impact on health care use after hospitalization with COVID-19 compared to hospitalization with RSV infection or other RTIs. The etiological mechanisms for potentially worse post-hospitalization complaints or health-seeking behavior for COVID-19 than for other RTIs in children should be further explored.