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Cited by 168Long-Term Effects of COVID-19COVID-19 Clinical Research StudiesCOVID-19 and Mental Health

Long COVID symptoms in SARS-CoV-2-positive adolescents and matched controls (LongCOVIDKidsDK): a national, cross-sectional study

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Kikkenborg Berg, Selina, Dam Nielsen, Susanne, Nygaard, Ulrikka, Bundgaard, Henning, Palm, Pernille, Rotvig, Camilla, Vinggaard Christensen, Anne·2022·The Lancet Child & Adolescent Health
DOI 10.1016/s2352-4642(22)00004-9PMC PMC8820960
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Abstract

Background Many adolescents have been affected by the COVID-19 pandemic either directly by being infected with the virus or indirectly by lockdowns and restrictions influencing normal living. We aimed to investigate health, including symptoms of long COVID, in adolescents (aged 15-18 years) who tested positive for SARS-CoV-2 compared with a control group. Methods LongCOVIDKidsDK was a national, cross-sectional study carried out in Denmark, which included SARS-CoV-2-positive adolescents and matched controls. All Danish adolescents aged 15-18 years with a positive SARS-CoV-2 test during the period Jan 1, 2020, to July 12, 2021, and a control group matched (1:4) by age and sex were sent a survey from July 20, 2021. Participants had until Sept 15, 2021, to respond. Symptoms associated with COVID-19, school attendance, and health-related quality of life were investigated using ancillary questions and validated questionnaires (Paediatric Quality of Life Inventory [PedsQL] and Children's Somatic Symptoms Inventory-24 [CSSI-24]). Statistical analyses included descriptive statistics and logistic regression. This study is registered at ClinicalTrials.gov, NCT04786353. Findings 24 315 adolescents with a positive SARS-CoV-2 test (case group) and 97 257 matched controls were invited to participate. 3013 matched controls were excluded because of suspected SARS-CoV-2 infection. 6630 (27·3%) responded in the case group and 21 640 (22·3%) responded and were eligible to participate in the control group. Across both groups, median age was 17·6 years (IQR 16·4-18·5), 16 277 (57·6%) of 28 270 responders were female, and 11 993 (42·4%) were male. Participants in the case group had greater odds of having at least one long COVID symptom lasting at least 2 months compared with the control group (3159 [61·9%] vs 12 340 [57·0%], odds ratio 1·22 [95% CI 1·15-1·30]; p<0·0001). Participants in the case group reported significantly lower symptom scores (ie, less somatic distress) on the CSSI-24 than in the control group: mean 10·7 (SD 11·4, median 7·0 [IQR 2·0-15·0]) versus 11·9 (10·6, 9·0 [4·0-17·0]; p<0·0001). Participants in the case group had better quality of life scores on the PedsQL than in the control group: physical functioning mean score 88·7 (SD 13·9, median 93·8 [IQR 84·4-100·0]) versus 86·5 (14·3, 90·6 [81·3-96·9]; p<0·0001); emotional functioning 77·1 (20·3, 80·0 [65·0-95·0]) versus 71·7 (21·4, 75·0 [60·0-90·0]; p<0·0001); social functioning 93·1 (12·5, 100·0 [90·0-100·0]) versus 88·4 (16·2, 95·0 [80·0-100·0]; p<0·0001); and school functioning 66·9 (22·5, 65·0 [60·0-85·0]) versus 62·9 (22·1, 65·0 [50·0-80·0]; p<0·0001). More participants in the case group than in the control group reported 16 or more sick days (1205 [18·2%] vs 2518 [11·6%]; p<0·0001) and 16 or more days of school absence (695 [10·5%] vs 1777 [8·2%]; p<0·0001). Interpretation Participants with SARS-CoV-2-positive tests had more long-lasting symptoms and sick leave, whereas participants in the control group had more short-lasting symptoms and worse quality of life. Knowledge of long COVID in adolescents is important to guide clinical recognition and management of this condition. Funding AP Møller and Chastine McKinney Møller Foundation.

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  • The rate of school absence has increased in numerous countries both during and following the pandemic.

    “The rate of school absence has increased in numerous countries both during and following the pandemic”

    From “So That You Can Feel Well”: Perspectives of Students with Social, Emotional and Behavioral Difficulties on Factors that Support School Attendance (2025) · cites this paper as Kikkenborg Berg et al., 2022

    The Introduction reports more school absences among SARS-CoV-2-positive adolescents than matched controls in Denmark during the pandemic, and the Discussion notes that quarantine restrictions could partly explain the difference. This does not establish that school-absence rates rose over time in numerous countries, either during or after the pandemic. (LLM, conf=0.84)

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Authors
Kikkenborg Berg, S., Dam Nielsen, S., Nygaard, U., Bundgaard, H., Palm, P., Rotvig, C., & Vinggaard Christensen, A.
Affiliations
  • University of Copenhagen (DK)
  • Copenhagen University Hospital (DK)
ORCID
Venue
The Lancet Child & Adolescent Health
Publisher
Elsevier BV
Published
2022-04
Volume
6
Issue
4
Pages
240-248
ISSN
2352-4642 (ISSN-L)
DOI
10.1016/s2352-4642(22)00004-9
PMC
PMC8820960
OpenAlex
W4210865126
Cited by
168
References
35
Citations by year
2026: 11 · 2025: 26 · 2024: 36 · 2023: 49 · 2022: 45
FWCI
20.54
Type
journal article
Language
en
Open access
Licence
Locations
  • The Lancet Child & Adolescent Health (publishedVersion)
  • PubMed Central (publishedVersion)
  • Research at the University of Copenhagen (University of Copenhagen) (publishedVersion, other-oa)
  • PubMed (publishedVersion)
Funders
  • Gilead Sciences
  • Meso Scale Diagnostics
  • GlaxoSmithKline
  • AP Møller Fonden
  • Novo Nordisk Fonden
Topics
  • Health Sciences › Medicine › Neurology › Long-Term Effects of COVID-19
  • Health Sciences › Medicine › Infectious Diseases › COVID-19 Clinical Research Studies
  • Social Sciences › Psychology › Clinical Psychology › COVID-19 and Mental Health
Keywords
long COVID, adolescents, COVID-19 pandemic, health-related quality of life, somatic symptoms, school attendance, matched controls, Denmark, lockdown effects
MeSH terms
COVID-19, SARS-CoV-2, COVID-19 Testing, Post-Acute COVID-19 Syndrome, Adolescent, Cross-Sectional Studies, Denmark, Female, Humans, Male, Quality of Life, Surveys and Questionnaires, Schools, Case-Control Studies, Sick Leave

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