{
  "abstract": "Background: The post‑acute sequelae of SARS‑CoV‑2 infection (PASC, “Long COVID”) remain difficult to evaluate because standardized diagnostic tools are limited. We applied the recently proposed PASC index (score ≥ 12) to describe the 12‑month trajectory of Long COVID symptoms. Methods: In this prospective cohort, adults with laboratory‑confirmed COVID‑19 were consecutively enrolled from November 2022 to February 2025. Long COVID was defined by a PASC index of ≥12 across 12 symptom domains persisting for at least 30 days post-infection. Symptom questionnaires were completed at 1, 3, 6 and 12 months after infection. Results: Among 183 participants, 48 (26.2%) met Long COVID criteria. Symptom assessments indicated that the proportion of participants meeting the Long COVID threshold declined from 27% at 1 month to 18% at 12 months, although this change was not statistically significant (p = 0.16). Participants classified as having Long COVID had consistently higher PASC index values across follow-up, while pairwise within-person comparisons showed no significant temporal changes in either the Long COVID or non-Long COVID group. These findings suggest that the overall symptom burden remained relatively stable over time, despite fluctuations in threshold status. Conclusion: During 12 months of follow-up, approximately one quarter of participants met the PASC index threshold at least once. Among participants with repeated assessments, PASC index scores showed limited within-person change, although differential non-response limits the interpretation of temporal prevalence estimates.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea"
  ],
  "article_type": "Research Article",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Kyungsup Kwon"
    },
    {
      "name": "Choi Young Jang"
    },
    {
      "name": "Woori Kim"
    },
    {
      "name": "JuYeon Son"
    },
    {
      "name": "Euijin Chang"
    },
    {
      "name": "Sung-Han Kim"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6ekbfqyvr3wth.bib",
  "cited_by": 0,
  "doi": "10.1371/journal.pone.0357670",
  "fulltext_url": null,
  "id": "6ekbfqyvr3wth",
  "issns": [
    "1932-6203"
  ],
  "landing_url": "https://doi.org/10.1371/journal.pone.0357670",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2728|Long-Term Effects of COVID-19"
    ],
    [
      "plos",
      "/Biology and life sciences/Immunology/Vaccination and immunization"
    ],
    [
      "plos",
      "/Biology and life sciences/Microbiology/Medical microbiology/Microbial pathogens/Viral pathogens/Coronaviruses/SARS coronavirus/SARS CoV 2"
    ],
    [
      "plos",
      "/Biology and life sciences/Organisms/Viruses/RNA viruses/Coronaviruses/SARS coronavirus/SARS CoV 2"
    ],
    [
      "plos",
      "/Biology and life sciences/Organisms/Viruses/Viral pathogens/Coronaviruses/SARS coronavirus/SARS CoV 2"
    ],
    [
      "plos",
      "/Medicine and health sciences/Clinical medicine/Signs and symptoms/Fatigue"
    ],
    [
      "plos",
      "/Medicine and health sciences/Diagnostic medicine/Virus testing"
    ],
    [
      "plos",
      "/Medicine and health sciences/Health care/Quality of life"
    ],
    [
      "plos",
      "/Medicine and health sciences/Immunology/Vaccination and immunization"
    ],
    [
      "plos",
      "/Medicine and health sciences/Medical conditions/Infectious diseases/Viral diseases/COVID 19"
    ],
    [
      "plos",
      "/Medicine and health sciences/Pathology and laboratory medicine/Pathogens/Microbial pathogens/Viral pathogens/Coronaviruses/SARS coronavirus/SARS CoV 2"
    ],
    [
      "plos",
      "/Medicine and health sciences/Public and occupational health/Preventive medicine/Vaccination and immunization"
    ],
    [
      "plos",
      "/Medicine and health sciences/Surgical and invasive medical procedures/Blood and lymphatic system procedures/Stem cell transplantation"
    ],
    [
      "plos",
      "/Medicine and health sciences/Surgical and invasive medical procedures/Transplantation/Cell transplantation/Stem cell transplantation"
    ],
    [
      "plos",
      "/Research and analysis methods/Research design/Survey research/Questionnaires"
    ]
  ],
  "openalex": "W7211942312",
  "pdf_url": "https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0357670&type=printable",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-08",
  "publisher": "Public Library of Science",
  "ris": "https://research.draconitic.com/paper/6ekbfqyvr3wth.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:56Z",
      "native_id": "10.1371/journal.pone.0357670",
      "source": "plos",
      "url": "https://doi.org/10.1371/journal.pone.0357670"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "plos:immunology",
      "subfield": "immunology"
    },
    {
      "field": "biology",
      "origin": "plos:microbiology",
      "subfield": "microbiology"
    },
    {
      "field": "medicine",
      "origin": "plos:surgical and invasive medical procedures",
      "subfield": "surgery"
    }
  ],
  "title": "Kinetics of the PASC Index in Long COVID",
  "title_text": "Kinetics of the PASC Index in Long COVID",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:56Z",
  "url": "https://research.draconitic.com/paper/6ekbfqyvr3wth",
  "venue": "PLOS One",
  "versions": []
}