Healthcare use attributable to COVID-19: a propensity-matched national electronic health records cohort study of 249,390 people in Wales, UK

• Published in: BMC medicine 2023-07, Vol.21 (1), p.259-259, Article 259
• Main Authors: Kennedy, J, Parker, M, Seaborne, M, Mhereeg, M, Walker, A, Walker, V, Denaxas, S, Kennedy, N, Katikireddi, S V, Brophy, S
• Format: Article
• Language: English
• Subjects: Analysis; Big data; Cohort analysis; Cohort Studies; COVID-19; COVID-19 - complications; COVID-19 - diagnosis; COVID-19 - epidemiology; COVID-19 Testing; Datasets; Delivery of Health Care; Disease; Electronic Health Records; Electronic medical records; Electronic records; Embolism; Fatigue; Fatigue tests; Health care; Health data; Hospitals; Humans; Illnesses; Infections; Long COVID; Medical care; Medical records; Mental disorders; Mortality; Pandemics; Patients; Polymerase chain reaction; Population; Population studies; Post-Acute COVID-19 Syndrome; Reverse transcription; Risk; Routine data; SARS-CoV-2; Self report; Severe acute respiratory syndrome coronavirus 2; Statistical analysis; Tables (data); Terminology; Utilization; Viral diseases; Virus Diseases; Wales - epidemiology
• ISSN: 1741-7015; 1741-7015
• DOI: 10.1186/s12916-023-02897-5

To determine the extent and nature of changes associated with COVID-19 infection in terms of healthcare utilisation, this study observed healthcare contact 1 to 4 and 5 to 24 weeks following a COVID-19 diagnosis compared to propensity-matched controls. Two hundred forty nine thousand three hundred ninety Welsh individuals with a positive reverse transcription-polymerase chain reaction (RT-PCR) test were identified from data from national PCR test results. After elimination criteria, 98,600 positive individuals were matched to test negative and never tested controls using propensity matching. Cohorts were split on test location. Tests could be taken in either the hospital or community. Controls were those who had tested negative in their respective environments. Survival analysis was utilised for first clinical outcomes which are grouped into primary and secondary. Primary outcomes include post-viral-illness and fatigue as an indication of long-COVID. Secondary outcomes include clinical terminology concepts for embolism, respiratory conditions, mental health conditions, fit notes, or hospital attendance. Increased instantaneous risk for positive individuals was quantified using hazard ratios (HR) from Cox regression, while absolute risk (AR) and relative risk were quantified using life table analysis. Analysis was conducted using all individuals and stratified by test location. Cases are compared to controls from the same test location. Fatigue (HR: 1.77, 95% CI: 1.34-2.25, p =