{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T22:04:18Z","timestamp":1790978658309,"version":"4.1.0"},"reference-count":40,"publisher":"Public Library of Science (PLoS)","issue":"9","license":[{"start":{"date-parts":[[2023,9,26]],"date-time":"2023-09-26T00:00:00Z","timestamp":1695686400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100023699","name":"Health Data Research UK","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100023699","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100000272","name":"National Institute for Health and Care Research","doi-asserted-by":"publisher","award":["COV-LT-0009"],"award-info":[{"award-number":["COV-LT-0009"]}],"id":[{"id":"10.13039\/501100000272","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100022512","name":"THIS Institute, University of Cambridge","doi-asserted-by":"publisher","award":["PD-2018-01-004"],"award-info":[{"award-number":["PD-2018-01-004"]}],"id":[{"id":"10.13039\/501100022512","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100014013","name":"UK Research and Innovation","doi-asserted-by":"publisher","award":["MR\/V033867\/1"],"award-info":[{"award-number":["MR\/V033867\/1"]}],"id":[{"id":"10.13039\/100014013","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000272","name":"National Institute for Health and Care Research","doi-asserted-by":"publisher","award":["AI_AWARD01864"],"award-info":[{"award-number":["AI_AWARD01864"]}],"id":[{"id":"10.13039\/501100000272","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100014013","name":"UK Research and Innovation","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100014013","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100000274","name":"British Heart Foundation","doi-asserted-by":"publisher","award":["AA\/18\/6\/24223"],"award-info":[{"award-number":["AA\/18\/6\/24223"]}],"id":[{"id":"10.13039\/501100000274","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100014013","name":"UK Research and Innovation","doi-asserted-by":"publisher","award":["MR\/V033867\/1"],"award-info":[{"award-number":["MR\/V033867\/1"]}],"id":[{"id":"10.13039\/100014013","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000272","name":"National Institute for Health and Care Research","doi-asserted-by":"publisher","award":["NIHR200179"],"award-info":[{"award-number":["NIHR200179"]}],"id":[{"id":"10.13039\/501100000272","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\">\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Long Covid is a widely recognised consequence of COVID-19 infection, but little is known about the burden of symptoms that patients present with in primary care, as these are typically recorded only in free text clinical notes.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec002\">\n                    <jats:title>Aims<\/jats:title>\n                    <jats:p>To compare symptoms in patients with and without a history of COVID-19, and investigate symptoms associated with a Long Covid diagnosis.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec003\">\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We used primary care electronic health record data until the end of December 2020 from The Health Improvement Network (THIN), a Cegedim database. We included adults registered with participating practices in England, Scotland or Wales. We extracted information about 89 symptoms and \u2018Long Covid\u2019 diagnoses from free text using natural language processing. We calculated hazard ratios (adjusted for age, sex, baseline medical conditions and prior symptoms) for each symptom from 12 weeks after the COVID-19 diagnosis.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec004\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>We compared 11,015 patients with confirmed COVID-19 and 18,098 unexposed controls. Only 20% of symptom records were coded, with 80% in free text. A wide range of symptoms were associated with COVID-19 at least 12 weeks post-infection, with strongest associations for fatigue (adjusted hazard ratio (aHR) 3.46, 95% confidence interval (CI) 2.87, 4.17), shortness of breath (aHR 2.89, 95% CI 2.48, 3.36), palpitations (aHR 2.59, 95% CI 1.86, 3.60), and phlegm (aHR 2.43, 95% CI 1.65, 3.59). However, a limited subset of symptoms were recorded within 7 days prior to a Long Covid diagnosis in more than 20% of cases: shortness of breath, chest pain, pain, fatigue, cough, and anxiety \/ depression.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec005\">\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Numerous symptoms are reported to primary care at least 12 weeks after COVID-19 infection, but only a subset are commonly associated with a GP diagnosis of Long Covid.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1371\/journal.pone.0290583","type":"journal-article","created":{"date-parts":[[2023,9,26]],"date-time":"2023-09-26T13:28:46Z","timestamp":1695734926000},"page":"e0290583","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":19,"title":["Long Covid symptoms and diagnosis in primary care: A cohort study using structured and unstructured data in The Health Improvement Network primary care database"],"prefix":"10.1371","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8907-5724","authenticated-orcid":true,"given":"Anoop D.","family":"Shah","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8875-7363","authenticated-orcid":true,"given":"Anuradhaa","family":"Subramanian","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6953-1852","authenticated-orcid":true,"given":"Jadene","family":"Lewis","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Samir","family":"Dhalla","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5613-8509","authenticated-orcid":true,"given":"Elizabeth","family":"Ford","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0096-1413","authenticated-orcid":true,"given":"Shamil","family":"Haroon","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Valerie","family":"Kuan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krishnarajah","family":"Nirantharakumar","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2023,9,26]]},"reference":[{"key":"pone.0290583.ref001","doi-asserted-by":"crossref","first-page":"n1648","DOI":"10.1136\/bmj.n1648","article-title":"Long covid-mechanisms, risk factors, and management","volume":"374","author":"H Crook","year":"2021","journal-title":"BMJ"},{"key":"pone.0290583.ref002","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1097\/MCP.0000000000000863","article-title":"A clinical review of long-COVID with a focus on the respiratory system","volume":"28","author":"L Daines","year":"2022","journal-title":"Curr Opin Pulm Med"},{"key":"pone.0290583.ref003","first-page":"1410768211032850","article-title":"Symptoms, complications and management of long COVID: a review.","author":"OL Aiyegbusi","year":"2021","journal-title":"J R Soc Med"},{"key":"pone.0290583.ref004","doi-asserted-by":"crossref","first-page":"103722","DOI":"10.1016\/j.ebiom.2021.103722","article-title":"Characterizing Long COVID: Deep Phenotype of a Complex Condition.","volume":"74","author":"RR Deer","year":"2021","journal-title":"EBioMedicine"},{"key":"pone.0290583.ref005","article-title":"Characterizing Long COVID in an international cohort: 7 months of symptoms and their impact.","author":"HE Davis","year":"2020","journal-title":"bioRxiv"},{"key":"pone.0290583.ref006","doi-asserted-by":"crossref","first-page":"104413","DOI":"10.1016\/j.ebiom.2022.104413","article-title":"Generalisable long COVID subtypes: findings from the NIH N3C and RECOVER programmes.","volume":"87","author":"JT Reese","year":"2023","journal-title":"EBioMedicine"},{"key":"pone.0290583.ref007","doi-asserted-by":"crossref","first-page":"ofac060","DOI":"10.1093\/ofid\/ofac060","article-title":"Identification of Distinct Long COVID Clinical Phenotypes Through Cluster Analysis of Self-Reported Symptoms","volume":"9","author":"G Kenny","year":"2022","journal-title":"Open Forum Infect Dis"},{"key":"pone.0290583.ref008","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1038\/s41591-022-02116-3","article-title":"Data-driven identification of post-acute SARS-CoV-2 infection subphenotypes","volume":"29","author":"H Zhang","year":"2023","journal-title":"Nat Med"},{"key":"pone.0290583.ref009","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1186\/s12916-023-02737-6","article-title":"Coding long COVID: characterizing a new disease through an ICD-10 lens.","volume":"21","author":"ER Pfaff","year":"2023","journal-title":"BMC Med"},{"key":"pone.0290583.ref010","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1038\/s41586-021-03553-9","article-title":"High-dimensional characterization of post-acute sequelae of COVID-19","volume":"594","author":"Z Al-Aly","year":"2021","journal-title":"Nature"},{"key":"pone.0290583.ref011","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1186\/s12916-021-02115-0","article-title":"Evolving phenotypes of non-hospitalized patients that indicate long COVID","volume":"19","author":"H Estiri","year":"2021","journal-title":"BMC Med"},{"key":"pone.0290583.ref012","doi-asserted-by":"crossref","first-page":"e532","DOI":"10.1016\/S2589-7500(22)00048-6","article-title":"Identifying who has long COVID in the USA: a machine learning approach using N3C data","volume":"4","author":"ER Pfaff","year":"2022","journal-title":"Lancet Digit Health"},{"key":"pone.0290583.ref013","doi-asserted-by":"crossref","first-page":"267","DOI":"10.3949\/ccjm.88a.21010","article-title":"Post-acute sequelae of SARS-CoV-2 infection: Caring for the \u2018long-haulers\u2019.","volume":"88","author":"S Vehar","year":"2021","journal-title":"Cleve Clin J Med"},{"key":"pone.0290583.ref014","article-title":"Symptoms and risk factors for long COVID in non-hospitalized adults","author":"A Subramanian","year":"2022","journal-title":"Nat Med"},{"key":"pone.0290583.ref015","unstructured":"Report: What Does COVID-19 Recovery Actually Look Like?\u2013Patient Led Research Collaborative. https:\/\/patientresearchcovid19.com\/research\/report-1\/ (accessed 3 Aug 2023)."},{"key":"pone.0290583.ref016","doi-asserted-by":"crossref","first-page":"626","DOI":"10.1038\/s41591-021-01292-y","article-title":"Attributes and predictors of long COVID","volume":"27","author":"CH Sudre","year":"2021","journal-title":"Nat Med"},{"key":"pone.0290583.ref017","article-title":"Risk factors and symptom clusters for Long Covid: analysis of United Kingdom symptom tracker app data.","author":"E Ford","year":"2022","journal-title":"medRxiv"},{"key":"pone.0290583.ref018","article-title":"Rapid implementation of mobile technology for real-time epidemiology of COVID-19","author":"DA Drew","year":"2020","journal-title":"Science"},{"key":"pone.0290583.ref019","doi-asserted-by":"crossref","first-page":"3528","DOI":"10.1038\/s41467-022-30836-0","article-title":"Long COVID burden and risk factors in 10 UK longitudinal studies and electronic health records.","volume":"13","author":"EJ Thompson","year":"2022","journal-title":"Nat Commun"},{"key":"pone.0290583.ref020","doi-asserted-by":"crossref","first-page":"m2815","DOI":"10.1136\/bmj.m2815","article-title":"Covid-19: What do we know about \u2018long covid\u2019?","volume":"370","author":"E. Mahase","year":"2020","journal-title":"BMJ"},{"key":"pone.0290583.ref021","article-title":"OpenSAFELY: factors associated with COVID-19-related hospital death in the linked electronic health records of 17 million adult NHS patients","author":"The OpenSAFELY Collaborative","year":"2020","journal-title":"Epidemiology"},{"key":"pone.0290583.ref022","doi-asserted-by":"crossref","first-page":"430","DOI":"10.1038\/s41586-020-2521-4","article-title":"Factors associated with COVID-19-related death using OpenSAFELY","volume":"584","author":"EJ Williamson","year":"2020","journal-title":"Nature"},{"key":"pone.0290583.ref023","article-title":"Clinical coding of long COVID in English primary care: a federated analysis of 58 million patient records in situ using OpenSAFELY.","author":"AJ Walker","year":"2021","journal-title":"Br J Gen Pract"},{"key":"pone.0290583.ref024","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1186\/s13326-019-0214-4","article-title":"Natural language processing for disease phenotyping in UK primary care records for research: a pilot study in myocardial infarction and death","volume":"10","author":"AD Shah","year":"2019","journal-title":"J Biomed Semantics"},{"key":"pone.0290583.ref025","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1145\/2064747.2064757","volume-title":"Proceedings of the first international workshop on Managing interoperability and complexity in health systems.","author":"R Koeling","year":"2011"},{"key":"pone.0290583.ref026","doi-asserted-by":"crossref","first-page":"364","DOI":"10.1093\/jamia\/ocy173","article-title":"Natural language processing of symptoms documented in free-text narratives of electronic health records: a systematic review","volume":"26","author":"TA Koleck","year":"2019","journal-title":"J Am Med Inform Assoc"},{"key":"pone.0290583.ref027","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1186\/1472-6947-12-88","article-title":"The Freetext Matching Algorithm: a computer program to extract diagnoses and causes of death from unstructured text in electronic health records","volume":"12","author":"AD Shah","year":"2012","journal-title":"BMC Med Inform Decis Mak"},{"key":"pone.0290583.ref028","first-page":"251","article-title":"Generalisability of The Health Improvement Network (THIN) database: demographics, chronic disease prevalence and mortality rates","volume":"19","author":"BT Blak","year":"2011","journal-title":"Inform Prim Care"},{"key":"pone.0290583.ref029","unstructured":"A clinical case definition of post COVID-19 condition by a Delphi consensus. World Health Organization, 2021 https:\/\/www.who.int\/publications\/i\/item\/WHO-2019-nCoV-Post_COVID-19_condition-Clinical_case_definition-2021.1."},{"key":"pone.0290583.ref030","article-title":"Translating and evaluating historic phenotyping algorithms using SNOMED CT","author":"M Elkheder","year":"2022","journal-title":"J Am Med Inform Assoc"},{"key":"pone.0290583.ref031","author":"R Foundation for Statistical Computing","year":"2022","journal-title":"R: A language and environment for statistical computing"},{"issue":"3","key":"pone.0290583.ref032","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1016\/j.jacc.2016.10.060","article-title":"Comparison of Propensity Score Methods and Covariate Adjustment: Evaluation in 4 Cardiovascular Studies","volume":"69","author":"MC Elze","year":"2017","journal-title":"J Am Coll Cardiol"},{"key":"pone.0290583.ref033","doi-asserted-by":"crossref","first-page":"1473","DOI":"10.1080\/07853890.2022.2076901","article-title":"Pathophysiology and mechanism of long COVID: a comprehensive review","volume":"54","author":"D Castanares-Zapatero","year":"2022","journal-title":"Ann Med"},{"key":"pone.0290583.ref034","article-title":"Characterising patterns of COVID-19 and long COVID symptoms: Evidence from nine UK longitudinal studies","author":"RCE Bowyer","year":"2022","journal-title":"bioRxiv"},{"key":"pone.0290583.ref035","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1186\/1471-2296-11-16","article-title":"Making the diagnosis of Chronic Fatigue Syndrome\/Myalgic Encephalitis in primary care: a qualitative study.","volume":"11","author":"C Chew-Graham","year":"2010","journal-title":"BMC Fam Pract"},{"key":"pone.0290583.ref036","article-title":"Recording problems and diagnoses in clinical care: developing guidance for healthcare professionals and system designers","volume":"26","author":"AD Shah","year":"2019","journal-title":"BMJ Health Care Inform"},{"key":"pone.0290583.ref037","doi-asserted-by":"crossref","first-page":"e000025","DOI":"10.1136\/bmjopen-2010-000025","article-title":"Using free text information to explore how and when GPs code a diagnosis of ovarian cancer: an observational study using primary care records of patients with ovarian cancer","volume":"1","author":"AR Tate","year":"2011","journal-title":"BMJ Open"},{"key":"pone.0290583.ref038","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1111\/j.1365-2125.2009.03537.x","article-title":"Validation and validity of diagnoses in the General Practice Research Database: a systematic review","volume":"69","author":"E Herrett","year":"2010","journal-title":"Br J Clin Pharmacol"},{"key":"pone.0290583.ref039","doi-asserted-by":"crossref","first-page":"e38122","DOI":"10.2196\/38122","article-title":"Deployment of a Free-Text Analytics Platform at a UK National Health Service Research Hospital: CogStack at University College London Hospitals.","volume":"10","author":"K Noor","year":"2022","journal-title":"JMIR Med Inform"},{"key":"pone.0290583.ref040","doi-asserted-by":"crossref","first-page":"6","DOI":"10.3389\/fdgth.2021.606599","article-title":"The Potential of Research Drawing on Clinical Free Text to Bring Benefits to Patients in the United Kingdom: A Systematic Review of the Literature","volume":"3","author":"E Ford","year":"2021","journal-title":"Frontiers in Digital Health"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0290583","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,10,29]],"date-time":"2024-10-29T01:33:09Z","timestamp":1730165589000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0290583"}},"subtitle":[],"editor":[{"given":"Sreeram V.","family":"Ramagopalan","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2023,9,26]]},"references-count":40,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2023,9,26]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0290583","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,9,26]]}}}