The DOI matches its Crossref record; 34 of the 35 references it cites were found in a registry or an index, and 1 are not checked yet.
Long COVID symptoms in SARS-CoV-2-positive adolescents and matched controls (LongCOVIDKidsDK): a national, cross-sectional study
Open accessAbstract
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.
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“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
Experimental — accuracy not yet measured
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cites
Harris, P. A., Taylor, R., Thielke, R., Payne, J., Gonzalez, N., & Conde, J. G. (2009) · Journal of Biomedical Informatics · doi:10.1016/j.jbi.2008.08.010 · Cited by 51,384
The Psychological Impact of Quarantine and How to Reduce It: Rapid Review of the Evidence
Brooks, S. K., Webster, R. K., Smith, L. E., Woodland, L., Wessely, S., Greenberg, N., & Rubin, G. J. (2020) · doi:10.2139/ssrn.3532534 · Cited by 16,394
The psychological impact of quarantine and how to reduce it: Rapid review of the evidence
Brooks, S. K., Webster, R. K., Smith, L. E., Woodland, L., Wessely, S., Greenberg, N., & Rubin, G. J. (2020) · The Lancet · doi:10.1016/s0140-6736(20)30460-8 · Cited by 16,378
Distribution Theory for Glass's Estimator of Effect Size and Related Estimators
Hedges, L. V. (1981) · Journal of Educational Statistics · doi:10.2307/1164588 · Cited by 5,695
A clinical case definition of post-COVID-19 condition by a Delphi consensus
Soriano, J. B., Murthy, S., Marshall, J. C., Relan, P., & Diaz, J. V. (2021) · The Lancet Infectious Diseases · doi:10.1016/s1473-3099(21)00703-9 · Cited by 3,075
Loades, M. E., Chatburn, E., Higson-Sweeney, N., Reynolds, S., Shafran, R., Brigden, A., Linney, C., McManus, M. N., Borwick, C., & Crawley, E. (2020) · Journal of the American Academy of Child & Adolescent Psychiatry · doi:10.1016/j.jaac.2020.05.009 · Cited by 2,906
Auerbach, R. P., Collaborators, W. W.-I., Mortier, P., Bruffaerts, R., Alonso, J., Benjet, C., Cuijpers, P., Demyttenaere, K., Ebert, D. D., Green, J. G., et al. (2018) · Journal of Abnormal Psychology · doi:10.1037/abn0000362 · Cited by 2,522
High-dimensional characterization of post-acute sequelae of COVID-19
Al-Aly, Z., Xie, Y., & Bowe, B. (2021) · Nature · doi:10.1038/s41586-021-03553-9 · Cited by 1,518
Magson, N. R., Freeman, J. Y. A., Rapee, R. M., Richardson, C. E., Oar, E. L., & Fardouly, J. (2021) · Journal of Youth and Adolescence · doi:10.1007/s10964-020-01332-9 · Cited by 1,498
Tenforde, M. W., Kim, S. S., Lindsell, C. J., Billig Rose, E., Shapiro, N. I., Files, D. C., Gibbs, K. W., Erickson, H. L., Steingrub, J. S., Smithline, H. A., et al. (2020) · MMWR. Morbidity and Mortality Weekly Report · doi:10.15585/mmwr.mm6930e1 · Cited by 1,319
Cited by
Sorted by citations
Collaborators, G. B. O. D. L. C., Hanson, S. W., Abbafati, C., Aerts, J. G. J. V., Al‐Aly, Z., Ashbaugh, C., Ballouz, T., Blyuss, O. B., Bobkova, P., Bonsel, G. J., et al. (2022) · JAMA · doi:10.1001/jama.2022.18931 · Cited by 1,015
Long-COVID in children and adolescents: a systematic review and meta-analyses
Lopez-Leon, S., Wegman-Ostrosky, T., Ayuzo del Valle, N. C., Perelman, C., Sepulveda, R., Rebolledo, P. A., Cuapio, A., & Villapol, S. (2022) · Scientific Reports · doi:10.1038/s41598-022-13495-5 · Cited by 528
Long covid outcomes at one year after mild SARS-CoV-2 infection: nationwide cohort study
Mizrahi, B., Sudry, T., Flaks‐Manov, N., Yehezkelli, Y., Kalkstein, N., Akiva, P., Ekka-Zohar, A., David, S. S. B., Lerner, U., Bivas‐Benita, M., et al. (2023) · BMJ · doi:10.1136/bmj-2022-072529 · Cited by 345
Kompaniyets, L., Bull–Otterson, L., Boehmer, T. K., Baca, S., Alvarez, P., Hong, K., Hsu, J., Harris, A. M., Gundlapalli, A. V., & Saydah, S. (2022) · MMWR Morbidity and Mortality Weekly Report · doi:10.15585/mmwr.mm7131a3 · Cited by 161
Prevalence and clinical presentation of long COVID in children: a systematic review
Pellegrino, R., Chiappini, E., Licari, A., Galli, L., & Marseglia, G. L. (2022) · European Journal of Pediatrics · doi:10.1007/s00431-022-04600-x · Cited by 152
Metadata
- 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)
- Venue
- The Lancet Child & Adolescent Health
- Publisher
- Elsevier BV
- Published
- 2022-04
- Volume
- 6
- Issue
- 4
- Pages
- 240-248
- ISSN
- 2352-4642 (ISSN-L)
- 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
- green
- www.ncbi.nlm.nih.gov
- 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 › Clinical 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
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
