Incidence and persistence of post-COVID condition in children – a matched cohort study in Germany

INTRODUCTION: Long-term health effects of COVID-19 have been investigated by several large cohort studies. As most of these studies have been conducted in adults, data on the incidence and persistence of post-COVID-19 condition (PCC) among children and adolescents are still limited. METHODS: Using routine healthcare data from statutory health insurance in Germany, children and adolescents with laboratory-confirmed COVID-19 in 2020 were matched to controls (neither documented nor clinically suspected COVID-19) and followed for incident health conditions until 2021-09-30. To study PCC in children we considered selected health outcomes including malaise/fatigue (R53), dyspnea (R06.0), and cognitive dysfunction (F06.7, U51, R41), developmental delay (F80-89), adjustment disorder (F43), chronic fatigue syndrome (CFS; G93.3), and altered smell/anosmia (R43). The incidence of PCC was determined based on the lack of related diagnoses in the 12 months preceding the index quarter. For each outcome incidence rate ratios (IRR) were estimated using Poisson regression. RESULTS: At 3-month-follow-up, about 40% more individuals with COVID-19 suffered from at least one of the specified health conditions compared to controls. IRR were highest for smell/anosmia and CFS. IRR were generally higher among adolescents (≥12 years) than among younger children. Only a minority of PCC diagnoses persisted for 12 months within the COVID cohort. Diagnoses were more frequently persistent in the younger age group after one year. CONCLUSIONS: Despite that long-term consequences of COVID-19 are less common and usually less severe in children, a considerable share of those diagnosed with PCC still suffered from specific symptoms 12 months after acute infection. Considering the high number of infected persons our findings suggest a relevant PCC related burden for health care even among children and adolescents. KEY MESSAGES: • In routine healthcare data adolescents showed stronger associations between COVID-19 and post COVID-19 related ICD-10 diagnoses than children < 12 years of age. • Serious ICD-10 diagnoses persisted for a longer time in younger children than adolescents.