Table 3.

Studies based on clinician-assessed data

Author	Age years	Type of study	Setting	Country	Children	Diagnostic test	Long COVID (N)	Long COVID (%)	Follow-up	Definition
Erol et al. [31]	Median age 9.16 IQR 10.88–17.92	Cross-sectional study Control group	Inpatients and outpatients SC HC	Turkey	121 COVID-19 95 controls** to compare instrumental cardiac findings	Not known	45	37.1%	Mean 5.6 m	Symptoms persisting at least 4 w after infection
Ashkenazi-Hoffnung et al. [17]	Mean age 12 SD 5 y	Prospective cohort study	Inpatients and outpatients SC HC	Israel	90	PCR Serological test	N/A	N/A	At least 4 m	Not expressed
Say et al. [13]	Median age 3 years (IQR 1–8)	Prospective cohort study	Inpatients and outpatients SC HC	Australia	151 149 After excluding PIMS-TS	Not known	12 10 After excluding PIMS-TS	8% 6.7% After excluding PIMS-TS	6 m	Symptoms lasting over 4 w
Smane et al. [23]	Median age 12 y (IQR 8–15)	Retrospective cohort study	Outpatients SC HC	Latvia	92	PCR	47	51%	3 m	Persistence of symptoms at least 1 m after infection
Heching et al. [25]	Median age 14.4 y (range 1–18 y)	Retrospective cohort study	Outpatients SC HC	US	82	PCR or antigen test	53	65%	44.5 ± 36.2 d	Prolonged symptoms following acute infection
Morrow et al. [35]	4–18 y	Case series	Outpatients SC HC	US	8	Clinical diagnosis 4 Serological test 1 PCR 4	8	N/A	Mean 7.2 m Range 2–11 m	Persistence of symptoms after acute infection
Morand et al. [34]	Mean age 12 y [range 10–13 y]	Case series	N/A SC HC	France	661 with SARS-CoV-2 infection	Clinical 4 Serological test 2 PCR 1	7	1.6%	4 w	Persisting symptoms more than 4 w from the acute infection without symptom-free interval

IQR interquartile range, N number, m months, SD standard deviations, y years, SC single centre, MC multi-centre, CW community-wide, HC health/hospital-centre, PCR polymerase chain reaction, N/A not applicable, PIMS-TS paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2, US United States of America, d days, w weeks