Examining potential Long COVID effects through utilization of healthcare resources: a retrospective, population-based, matched cohort study comparing individuals with and without prior SARS-CoV-2 infection

Abstract

Abstract Background A significant proportion of individuals reports persistent clinical manifestations following SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) acute infection. Nevertheless, knowledge of the burden of this condition—often referred to as ‘Long COVID’—on the health care system remains limited. This study aimed to evaluate healthcare utilization potentially related to Long COVID. Methods Population-based, retrospective, multi-center cohort study that analyzed hospital admissions and utilization of outpatient visits and diagnostic tests between adults aged 40 years and older recovered from SARS-CoV-2 infection occurred between February 2020 and December 2021 and matched unexposed individuals during a 6-month observation period. Healthcare utilization was analyzed by considering the setting of care for acute SARS-CoV-2 infection [non-hospitalized, hospitalized and intensive care unit (ICU)-admitted] as a proxy for the severity of acute infection and epidemic phases characterized by different SARS-CoV-2 variants. Data were retrieved from regional health administrative databases of three Italian Regions. Results The final cohort consisted of 307 994 previously SARS-CoV-2 infected matched with 307 994 uninfected individuals. Among exposed individuals, 92.2% were not hospitalized during the acute infection, 7.3% were hospitalized in a non-ICU ward and 0.5% were admitted to ICU. Individuals previously infected with SARS-CoV-2 (vs. unexposed), especially those hospitalized or admitted to ICU, reported higher utilization of outpatient visits (range of pooled Incidence Rate Ratios across phases; non-hospitalized: 1.11–1.33, hospitalized: 1.93–2.19, ICU-admitted: 3.01–3.40), diagnostic tests (non-hospitalized: 1.35–1.84, hospitalized: 2.86–3.43, ICU-admitted: 4.72–7.03) and hospitalizations (non-hospitalized: 1.00–1.52, hospitalized: 1.87–2.36, ICU-admitted: 4.69–5.38). Conclusions This study found that SARS-CoV-2 infection was associated with increased use of health care in the 6 months following infection, and association was mainly driven by acute infection severity.