Long COVID and the mental and physical health of children and young people: national matched cohort study protocol (the CLoCk study).

INTRODUCTION: There is uncertainty surrounding the diagnosis, prevalence, phenotype, duration and treatment of Long COVID. This study aims to (A) describe the clinical phenotype of post-COVID symptomatology in children and young people (CYP) with laboratory-confirmed SARS-CoV-2 infection compared with test-negative controls, (B) produce an operational definition of Long COVID in CYP, and (C) establish its prevalence in CYP. METHODS AND ANALYSIS: A cohort study of SARS-CoV-2-positive CYP aged 11-17 years compared with age, sex and geographically matched SARS-CoV-2 test-negative CYP. CYP aged 11-17 testing positive and negative for SARS-CoV-2 infection will be identified and contacted 3, 6, 12 and 24 months after the test date. Consenting CYP will complete an online questionnaire. We initially planned to recruit 3000 test positives and 3000 test negatives but have since extended our target. Data visualisation techniques will be used to examine trajectories over time for symptoms and variables measured repeatedly, separately by original test status. Summary measures of fatigue and mental health dimensions will be generated using dimension reduction methods such as latent variables/latent class/principal component analysis methods. Cross-tabulation of collected and derived variables against test status and discriminant analysis will help operationalise preliminary definitions of Long COVID. ETHICS AND DISSEMINATION: Research Ethics Committee approval granted. Data will be stored in secure Public Health England servers or University College London's Data Safe Haven. Risks of harm will be minimised by providing information on where to seek support. Results will be published on a preprint server followed by journal publication, with reuse of articles under a CC BY licence. Data will be published with protection against identification when there are small frequencies involved. TRIAL REGISTRATION NUMBER: ISRCTN34804192; Pre-results

Long COVID (post-COVID-19 condition) in children: a modified Delphi process

OBJECTIVE: The aim of this study was to derive a research definition for 'Long COVID (post-COVID-19 condition)' in children and young people (CYP) to allow comparisons between research studies. DESIGN: A three-phase online Delphi process was used, followed by a consensus meeting. Participants were presented with 49 statements in each phase and scored them from 1 to 9 based on how important they were for inclusion in the research definition of Long COVID in CYP. The consensus meeting was held to achieve representation across the stakeholder groups. Statements agreed at the consensus meeting were reviewed by participants in the Patient and Public Involvement (PPI) Research Advisory Group. SETTING: The study was conducted remotely using online surveys and a virtual consensus meeting. PARTICIPANTS: 120 people with relevant expertise were divided into three panels according to their area of expertise: Service Delivery, Research (or combination of research and service delivery) and Lived Experience. The PPI Research Advisory group consisted of CYP aged 11-17 years. MAIN OUTCOME MEASURES: Consensus was defined using existing guidelines. If consensus was achieved in two or more panels or was on the border between one and two panels, those statements were discussed and voted on at the consensus meeting. RESULTS: Ten statements were taken forward for discussion in the consensus meeting and five statements met threshold to be included in the research definition of Long COVID among CYP. The research definition, aligned to the clinical case definition of the WHO, is proposed as follows: Post-COVID-19 condition occurs in young people with a history of confirmed SARS-CoV-2 infection, with at least one persisting physical symptom for a minimum duration of 12 weeks after initial testing that cannot be explained by an alternative diagnosis. The symptoms have an impact on everyday functioning, may continue or develop after COVID infection, and may fluctuate or relapse over time. The positive COVID-19 test referred to in this definition can be a lateral flow antigen test, a PCR test or an antibody test. CONCLUSIONS: This is the first research definition of Long COVID (post-COVID-19 condition) in CYP and complements the clinical case definition in adults proposed by the WHO

Long COVID in children and young after infection or reinfection with the Omicron variant: a prospective observational study

To describe the prevalence of long COVID in children infected for the first time (n = 332) or reinfected (n = 243) with Omicron compared with test-negative children (n = 311). Overall, 12%-16% of those infected with Omicron met the research definition of long COVID at 3 and 6 months after infection, with no evidence of difference between cases of first positive and reinfected (Pχ2 = 0.17)

Long COVID in Children and Youth After Infection or Reinfection with the Omicron Variant: A Prospective Observational Study

To describe the prevalence of long COVID in children infected for the first time (n=332) or reinfected (n=243) with Omicron variant SARS-CoV-2, compared with test-negative children (n=311). 12-16% infected with Omicron met the research definition of long COVID at 3 and 6 months after infection, with no evidence of difference between cases of first-positive and reinfection (pchi-square=0.17)

The CLoCk study: A retrospective exploration of loneliness in children and young people during the COVID-19 pandemic, in England

BACKGROUND: During the COVID-19 pandemic children and young people (CYP) were socially restricted during a stage of life crucial to development, potentially putting an already vulnerable population at higher risk of loneliness, social isolation, and poorer wellbeing. The objectives of this study are to conduct an exploratory analysis into loneliness before and during the pandemic, and determine which self-reported factors are associated with loneliness. METHODS AND FINDINGS: Participants from The Children with Long COVID (CLoCk) national study were invited to take part via an online survey, with a total of 31,017 participants taking part, 31,016 of which reported on their experience of loneliness. Participants retrospectively answered questions on demographics, lifestyle, physical health and mental health and loneliness before the pandemic and at the time of answering the survey. Before the pandemic 6.5% (2,006/31,016) of participants reported experiencing loneliness "Often/Always" and at the time of survey completion 17.4% (5,395/31,016) reported feeling lonelier. There was an association between meeting the research definition of long COVID and loneliness [3.49 OR, 95%CI 3.28-3.72]. CYP who reported feeling lonelier at the time of the survey than before the pandemic were assigned female at birth, older CYP, those from Black/African/Caribbean/Black British or other ethnicity groups, those that had 3-4 siblings and lived in more deprived areas. CONCLUSIONS: We demonstrate associations between multiple factors and experiences of loneliness during the pandemic. There is a need for a multi-faceted integrated approach when developing interventions targeted at loneliness. It is important to follow up the CYP involved at regular intervals to investigate the progression of their experience of loneliness over time

Symptom Profiles of Children and Young People 12 Months after SARS-CoV-2 Testing: A National Matched Cohort Study (The CLoCk Study)

Background: Although 99% of children and young people have been exposed to SARS-CoV-2, the long-term prevalence of post-COVID-19 symptoms in young people is unclear. The aim of this study is to describe symptom profiles 12 months after SARS-CoV-2 testing. Method: A matched cohort study of a national sample of 20,202 children and young people who took a SARS-CoV-2 PCR test between September 2020 and March 2021. Results: 12 months post-index-test, there was a difference in the number of symptoms reported by initial negatives who never tested positive (NN) compared to the other three groups who had at least one positive test (p < 0.001). Similarly, 10.2% of the NN group described five-plus symptoms at 12 months compared to 15.9–24.0% in the other three groups who had at least one positive test. The most common symptoms were tiredness, sleeping difficulties, shortness of breath, and headaches for all four groups. For all these symptoms, the initial test positives with subsequent reports of re-infection had higher prevalences than other positive groups (p < 0.001). Symptom profiles, mental health, well-being, fatigue, and quality of life did not vary by vaccination status. Conclusions: Following the pandemic, many young people, particularly those that have had multiple SARS-CoV-2 positive tests, experience a range of symptoms that warrant consideration and potential investigation and intervention

Long COVID (post-COVID-19 condition) in children: a modified Delphi process

Objective The aim of this study was to derive a research definition for ‘Long COVID (post-COVID-19 condition)’ in children and young people (CYP) to allow comparisons between research studies. Design A three-phase online Delphi process was used, followed by a consensus meeting. Participants were presented with 49 statements in each phase and scored them from 1 to 9 based on how important they were for inclusion in the research definition of Long COVID in CYP. The consensus meeting was held to achieve representation across the stakeholder groups. Statements agreed at the consensus meeting were reviewed by participants in the Patient and Public Involvement (PPI) Research Advisory Group. Setting The study was conducted remotely using online surveys and a virtual consensus meeting. Participants 120 people with relevant expertise were divided into three panels according to their area of expertise: Service Delivery, Research (or combination of research and service delivery) and Lived Experience. The PPI Research Advisory group consisted of CYP aged 11–17 years. Main outcome measures Consensus was defined using existing guidelines. If consensus was achieved in two or more panels or was on the border between one and two panels, those statements were discussed and voted on at the consensus meeting. Results Ten statements were taken forward for discussion in the consensus meeting and five statements met threshold to be included in the research definition of Long COVID among CYP. The research definition, aligned to the clinical case definition of the WHO, is proposed as follows: Post-COVID-19 condition occurs in young people with a history of confirmed SARS-CoV-2 infection, with at least one persisting physical symptom for a minimum duration of 12 weeks after initial testing that cannot be explained by an alternative diagnosis. The symptoms have an impact on everyday functioning, may continue or develop after COVID infection, and may fluctuate or relapse over time. The positive COVID-19 test referred to in this definition can be a lateral flow antigen test, a PCR test or an antibody test. Conclusions This is the first research definition of Long COVID (post-COVID-19 condition) in CYP and complements the clinical case definition in adults proposed by the WHO

Long COVID (post-COVID-19 condition) in children: a modified Delphi process

Objective The aim of this study was to derive a research definition for ‘Long COVID (post-COVID-19 condition)’ in children and young people (CYP) to allow comparisons between research studies. Design A three-phase online Delphi process was used, followed by a consensus meeting. Participants were presented with 49 statements in each phase and scored them from 1 to 9 based on how important they were for inclusion in the research definition of Long COVID in CYP. The consensus meeting was held to achieve representation across the stakeholder groups. Statements agreed at the consensus meeting were reviewed by participants in the Patient and Public Involvement (PPI) Research Advisory Group. Setting The study was conducted remotely using online surveys and a virtual consensus meeting. Participants 120 people with relevant expertise were divided into three panels according to their area of expertise: Service Delivery, Research (or combination of research and service delivery) and Lived Experience. The PPI Research Advisory group consisted of CYP aged 11–17 years. Main outcome measures Consensus was defined using existing guidelines. If consensus was achieved in two or more panels or was on the border between one and two panels, those statements were discussed and voted on at the consensus meeting. Results Ten statements were taken forward for discussion in the consensus meeting and five statements met threshold to be included in the research definition of Long COVID among CYP. The research definition, aligned to the clinical case definition of the WHO, is proposed as follows: Post-COVID-19 condition occurs in young people with a history of confirmed SARS-CoV-2 infection, with at least one persisting physical symptom for a minimum duration of 12 weeks after initial testing that cannot be explained by an alternative diagnosis. The symptoms have an impact on everyday functioning, may continue or develop after COVID infection, and may fluctuate or relapse over time. The positive COVID-19 test referred to in this definition can be a lateral flow antigen test, a PCR test or an antibody test. Conclusions This is the first research definition of Long COVID (post-COVID-19 condition) in CYP and complements the clinical case definition in adults proposed by the WHO