UCL Great Ormond Street Institute of Child Health


Great Ormond Street Institute of Child Health


About The Study

A Brief Summary of CLoCk

The CLoCk study of Long Covid in children and young people (CYP) is funded by NIHR. It has three aims.

1) To describe what happens to children and young people in the months after they have COVID-19

2) To agree what is meant by ‘Long COVID’ or ‘Post COVID-19 Condition’ in CYP to help researchers compare findings

3) To help understand how many CYP in England are likely have Long COVID.

What is CLoCk?

How is CLoCk Doing This?

This project has identified test positive and test negative 11–17-year-olds through Public Health England’s database. We will be  contacting families 3, 6, 12 and 24 months after the young person’s COVID-19 test asking them to complete a questionnaire about the young person’s physical and mental health. We will compare the symptoms between those who have tested positive and those who do not, and also track symptoms over time.

3-Month Paper: A Summary of Findings

We have published the results from 6,804 CYP (3,065 test-positives, 3,739 test-negatives) who completed the questionnaire 3 months after their PCR test. 35% of the young people who tested positive said they showed symptoms at the time of testing and and this almost doubled after 3 months. Less than 10% of the children with a negative test showed symptoms during testing; 3 months later, this number increased and more than half had symptoms. Three months after their test, 30·3% of those who tested positive and 16·2% of those who tested negative had more than three symptoms.

After 3 months, the most common symptoms in children who tested positive were tiredness, headache, and shortness of breath. Those who tested were more likely to feel tiredness, headache and “other”.

A Research Definition of Long Covid in Children and Young People (CYP)

We conducted what is called a Delphi Consensus Process to reach a definition of Long Covid in CYP. This involved parents and children with lived experience, researchers and clinicians. The definition that was agreed for researchers and is similar to that used by the World Health Organisation is:

Post-COVID-19 condition occurs in young people with a history of confirmed SARS CoV2 infection, with one or more 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-19 infection, and may fluctuate or relapse over time.

You can find the Delphi paper here.

You can find out more about what a Delphi Process is from this video:

YouTube Widget Placeholderhttps://www.youtube.com/watch?v=ESxuo1CePZI&ab_channel=TimeManagementand...


Patient Public Involvement (PPI)

PPI involvement is at the heart of our work and led by Emma Dalrymple. We have a diverse group of Children and Young People meeting regularly to help inform the project.