ABSTRACT
BACKGROUND: Risk stratification models have been developed to identify patients that are at a higher risk of COVID-19 infection and severe illness. Objectives To develop and implement a scoring tool to identify COVID-19 patients that are at risk for severe illness during the Omicron wave. METHODS: This is a retrospective cohort study that was conducted in Israel's second-largest healthcare maintenance organization. All patients with a new episode of COVID-19 between 26 November 2021 and 18 January 2022 were included. A model was developed to predict severe illness (COVID-19-related hospitalization or death) based on one-third of the study population (the train group). The model was then applied to the remaining two-thirds of the study population (the test group). Risk score sensitivity, specificity, and positive predictive value rates, and receiver operating characteristics (ROC) were calculated to describe the performance of the model. RESULTS: A total of 409,693 patients were diagnosed with COVID-19 over the two-month study period, of which 0.4% had severe illness. Factors that were associated with severe disease were age (age > 75, OR-70.4, 95% confidence interval [CI] 42.8-115.9), immunosuppression (OR-4.8, 95% CI 3.4-6.7), and pregnancy (5 months or more, OR-82.9, 95% CI 53-129.6). Factors that were associated with a reduced risk for severe disease were vaccination status (patients vaccinated in the previous six months OR-0.6, 95% CI 0.4-0.8) and a prior episode of COVID-19 (OR-0.3, 95% CI 0.2-0.5). According to the model, patients who were in the 10th percentile of the risk severity score were considered at an increased risk for severe disease. The model accuracy was 88.7%. CONCLUSIONS: This model has allowed us to prioritize patients requiring closer follow-up by their physicians and outreach services, as well as identify those that are most likely to benefit from anti-viral treatment during the fifth wave of infection in Israel, dominated by the Omicron variant.
ABSTRACT
BACKGROUND: Intramuscular AZD7442 (Tixagevimab-Cilgavimab, (Evusheld)) has been found effective among immunocompromised individuals (ICI) in reducing Sars-Cov-2 infection and severe disease in ICIs. We evaluated the association between AZD7442 administration and SARS-CoV-2 infection and severe disease (COVID-19 hospitalization and all-cause mortality) among selected ICIs, during a fifth Omicron-dominated wave of COVID-19 (Dec 2021-April 2022) in Israel. METHODS: ICIs aged 12 and over identified in the Maccabi HealthCare Services database were invited by SMS/email to receive AZD7442. Demographic information, comorbidities, coronavirus vaccination and prior SARS-CoV-2 infection and COVID-19 outcome data (infection, severe disease), were extracted from the database. Rates of infection and severe disease were compared between those administered AZD7442 and those who did not respond to the invitation, over a three-month period. RESULTS: Of all 825 ICIs administered AZD7442, 29 (3.5%) became infected with SARS-CoV-2 compared to 308 (7.2%) of 4299 ICIs not administered AZD7442 (p < 0.001). After adjustment, the AZD7442 group were half as less likely to become infected with Sars-Cov-2 than the non-administered group (OR: 0.51, 95% CI: 0.30-0.84). One person in the AZD7442 group (0.1%) was hospitalized for COVID-19 compared to 27 (0.6%) in the non-administered group (p = 0.07). No mortality was recorded among the AZD7442 group, compared to 40 deaths (0.9%) in the non-administered group (p = 0.005). After adjustment, ICIs administered AZD7442 were 92% less likely to be hospitalized/die than those not administered AZD7442 (OR: 0.08, 95% CI: 0.01-0.54). CONCLUSIONS: AZD7442 among ICI may protect against Omicron variant infection and severe disease, and should be considered for pre-exposure prophylactic AZD7442.