Children and young people with persistent post-COVID-19 condition over 24 months: a mixed-methods study.

Purpose: While most children and young people (CYP) recover from COVID-19, some develop 'post-COVID-19 condition' (PCC), affecting their health and well-being. We explored (1) whether distinct persistent PCC symptom subgroups exist in CYP and whether these subgroups remain stable up to 24 months postinfection; (2) whether impairments differ across subgroups and (3) how CYP with persistent PCC describe the evolving impact of the pandemic/lockdowns on their health and experiences up to 24 months postinfection.

Methods: A cohort of CYP across England was recruited in 2020-2021 (the children and young people with Long COVID study). A subsample of 68 CYP meeting the PCC Delphi research definition at 3, 6, 12 and 24 months post-PCR-confirmed infection was analysed. Latent class analysis identified symptom subgroups (objective 1); associations with impairments (measured via EuroQol Five Dimensions Youth) were examined (objective 2). Free-text responses from six CYP at all four follow-up points (n=24) were thematically analysed to capture evolving experiences (objective 3).

Results: Included CYP were older (72.1% were 15-17 years), female (82.4%) and white (80.9%). Two symptom groups emerged: a frequent symptom subgroup (median: 6.5-9 symptoms over time, mainly shortness of breath and tiredness); and a less frequent symptom subgroup (median: 4-5 symptoms, mostly tiredness). Generally, no association was found between symptom subgroups and impairments. Qualitative analysis indicated feelings of anxiety, respiratory problems and concerns around relaxation of lockdown restrictions persisted over follow-up. School-related worries were transient.

Discussion: Even CYP with persistent PCC characterised by fewer symptoms experience long-term anxiety and impact, emphasising even few symptoms can be debilitating and underscoring the need for personalised PCC management for CYP.