Table.

Characteristics of school-aged children who tested positive for SARS-CoV-2, and the control cohort of children (matched 1:1 for age, gender, and week of testing) who tested negative for SARS-CoV-2

	Children with positive SARS-CoV-2 test (n=1734)					Children with negative SARS-CoV-2 test (matched cohort, n=1734)
	Younger group (aged 5–11 years, n=588)	Older group (aged 12–17 years, n=1146)	Symptom duration <10 days (n=1183)	Symptom duration ≥28 days (n=77)	Full cohort (n=1734)
Females	301 (51·2%)	569 (49·7%)	565 (47·8%)	42 (54·5%)	870 (50·2%)	869 (50·1%)
Males	287 (48·8%)	577 (50·3%)	618 (52·2%)	35 (45·5%)	864 (49·8%)	865 (49·9%)
Age, years	9 (7–10)	15 (13–16)	13 (10–15)	14 (12–16)	13 (10–15)	13 (10–15)
Body-mass index (kg/m2)	17·0 (15·1–19·7)	20·1 (17·8–22·3)	19·0 (16·5–21·8)	18·6 (16·3–21·8)	19·2 (16·6–21·8)	19·0 (16·5–21·5)
Asthma	69 (11·7%)	147 (12·8%)	134 (11·3%)	10 (13·0%)	216 (12·5%)	229 (13·2%)
Heart disease	1 (0·2%)	1 (0·1%)	2 (0·2%)	0	2 (0·1%)	0
Diabetes	2 (0·3%)	5 (0·4%)	4 (0·3%)	0	7 (0·4%)	6 (0·3%)
Renal disease	0	2 (0·2%)	0	1 (1·3%)	2 (0·1%)	4 (0·2%)
Presentation to hospital	16 (2·7%)	21 (1·8%)	20 (1·7%)	1 (1·3%)	37 (2·1%)	26 (1·5%)
Illness duration, days	5 (2–9)	7 (3–12)	4 (2–6)	46 (32–58)	6 (3–11)	3 (2–7)
Number of symptoms in the first week	3 (2–5)	4 (2–6)	3 (2–5)	6 (4–8)	3 (2–6)	2 (1–4)

Data are n (%) or median (IQR). The cohort of children with positive SARS-CoV-2 testing is presented here both as younger and older groups, and for usual (ie, short) versus extended illness duration. Data refers to children with symptom onset between Sept 1, 2020, and Jan 24, 2021. Common paediatric comorbidities such as neurological or neurodisability disorders (eg, cerebral palsy) were not assessed. Presentation to hospital included presenting to the emergency department or admission to hospital.