Table 1.

Data used to estimate hospitalisations, deaths, Intensive Care Unit admissions, vaccine-associated myocarditis and long COVID.

	Numbers	Percentage of cases
Total population 12–17 year olds	3,918,373
Boys	2,011,458
Girls	1,906,915
COVID-19 diagnosed cases 1 July 2020–31 March 2021	169,412
Hospitalised	1390	0.820
Intensive Care Unit admissions	91	0.054
Ventilated in Intensive Care Unit or outside Intensive Care Unit setting	75	0.044
Died	11	0.006
Long COVID (12 weeks) (2%,4% and 14% incidence)6–10	6,776 (4%)	2, 4, 14
Vaccine-associated myocarditis/pericarditis
Boys (12–17 year old) (per million)17–20	6.72 (1st dose) 62.75 (2nd dose)
Girls (12–17 year old) (per million)17–20	0 (1st dose) 8.68 (2nd dose)

Note: These data have been extracted through linkage of electronic health records from multiple sources to assess the total number of children identified with a COVID-19 infection, and related hospitalisations, intensive care admissions, ventilatory support and deaths (data accessed through the British Heart Foundation Data Science Centre). ¹⁵ Data sources include Second Generation Surveillance System national testing laboratory, primary care consultations in General Practice Extraction Service Data for Pandemic Planning and Research using SNOMED-CT terms, Hospitalisations are identified from an admission in Hospital Episode Statistics Admitted Patient Care or Secondary Uses Service containing COVID-19 ICD-10 diagnosis or an entry in COVID-19 Hospitalisations in England Surveillance System. Intensive Care Unit admissions are identified by an entry in Hospital Episode Statistics Critical Care or from. Ventilatory support is identified from the COVID-19 Hospitalisations in England Surveillance System, Hospital Episode Statistics Critical Care (basic or advanced respiratory support days > 0) and Hospital Episode Statistics Admitted Patient Care and Secondary Uses Service (OPCS-4 procedure codes for continuous positive airway pressure, non-invasive ventilation, invasive ventilation, intubation of trachea and extracorporeal membrane oxygenation). Deaths are identified from Office of National Statistics Deaths Registry, with COVID-19 as a named cause of death or within 28 days of an individual's first COVID-19 event as well as from Hospital Episode Statistics Admitted Patient Care or Secondary Uses Service admissions with a discharge method or destination denoting death. Patients were included in the analyses if they resided in England, were alive on the study start date, registered with a primary care practice, had a valid pseudo-identifier for linkage and at least 28 days of follow-up. We used the period from 1 July 2020 to 31 March 2021 to exclude the first wave of infections when few children were tested for COVID-19. ¹⁵

Total number of 12–17yr olds taken from Office for National Statistics population estimates for England: mid-2020 for persons by single year of age.