Exploring post-Covid-19 condition in children and young people 3.5 years after infection: a mixed-methods analysis from the CLoCk study

Abstract Background Comprehensive data on the persistence of Post-COVID-19 Condition (PCC; also known as Long COVID) and its impact on children and young people (CYP), incorporating their own perspective, is crucial to enhance our understanding of the condition, improve service provision and inform clinical management. Methods We examine long-term symptoms, health, and well-being among CYP persistently meeting PCC criteria up to 3.5-years after SARS-CoV-2 infection (when they were aged between 11-to-17-years), using a mixed-methods approach. 68 CYP from the CLoCk study who persistently met PCC criteria at 3- (April-June 2021), 6- (July–September 2021), 12- (January-March 2022), and 24-months (January-March 2023) post-infection were invited to complete an additional follow-up (October–November 2024). The survey assessed current symptoms and health status using validated measures, and symptom experiences through open-text responses. Quantitative data were analysed descriptively; qualitative data were analysed using thematic framework analysis. Findings were integrated using a convergent parallel design. Results 50 CYP completed the survey; of these 42 (84%) responders continued to meet the PCC definition 3.5-years post-infection. All 42 (100%) reported tiredness and 34 (81%) reported 5 + symptoms 3.5-years post-infection. Qualitative analysis reinforced tiredness as a central symptom, alongside co-occurring symptoms that impact daily life. While quantitative and qualitative findings largely converged, context as to why CYP reported high levels of impact were only available from qualitative data. Conclusions CYP with PCC persisting for 3.5-years post-infection experience multiple symptoms of wide-ranging severity and disruption to daily life, education and social participation.