OP0285 COVID-19 HOSPITALIZATIONS, ICU ADMISSION, AND DEATH AMONG PATIENTS WITH IMMUNE MEDIATED INFLAMMATORY DISEASES (IMID) – A POPULATION-BASED STUDY
Authors: L. Eder, R. Croxford, A. Drucker, A. Mendel, K. Bindee, Z. Touma, R. Cook, S. Johnson, S. Bernatsky, N. Haroon, J. Widdifield
Journal: Annals of the Rheumatic Diseases (2021)

Background: It remains unclear whether patients with IMID are at greater risk for severe COVID-19. Objectives: To investigate the risk of COVID-19 hospitalizations and their outcomes in patients with IMID compared with matched non-IMID patents from the general population. Methods: A population-based, matched cohort study was conducted in adults living in Ontario, Canada using health administrative data. Ten cohorts of the following IMID were assembled: rheumatoid arthritis, psoriasis, psoriatic arthritis, ankylosing spondylitis, systemic autoimmune rheumatic diseases (SARDs, including systemic lupus, systemic sclerosis, Sjogren’s, myositis), multiple sclerosis (MS), iritis, inflammatory bowel disease, polymyalgia rheumatica (PMR), and vasculitis (including giant cell arteritis and other types of vasculitidies). Each patient was matched with 5 non-IMID comparators based on age, sex, area of residence and living in long-term care (LTC). Patients who were admitted to hospital from January 1 st to July 31 th , 2020 and had ICD-10 COVID-19 diagnosis codes (U07.2 or U07.1) were identified. Among those with COVID-19 hospitalizations, we determined those with admissions to intensive care unit or required mechanical ventilation or died in hospital (‘complicated hospitalization’). Age-sex-standardized rates were compared between IMID and non-IMID patients and risk factors for hospitalizations were identified by multivariable logistic regression analysis. Results: In total, 493,499 IMID (417 hospitalized) and 2,466,946 non-IMID patients (1,519 hospitalized) were assessed. The age-sex-standardized rate of COVID-19 hospitalization was higher in IMID (6.4 per 10,000, 95% confidence interval (CI) 5.8, 7.2) versus non-IMID patients (4.8 per 100,000, 95% CI 4.5, 5). The highest rates of hospitalizations were found in vasculitis (18/10,000), MS (16.7/10,000) and PMR (10.1/10,000). IMID diagnosis was associated with 37% higher risk of being hospitalized for COVID-19 (Odds Ratio (OR) 1.37, 95% CI 1.23, 1.53) (Figure 1). This risk was slightly attenuated after adjusting for sociodemographic factors and comorbidities but remained elevated by 23% compared to non-IMID (OR 1.23, 95% CI 1.10, 1.37). The risk for hospitalizations was increased in RA, vasculitis, SARDs, PsA, MS and iritis (Figure 1). Risk factors for COVID-19 hospitalizations included older age, male sex, lower income, multimorbidity and living in long-term care (Table 1). The risk for complicated COVID-19 hospitalizations was higher by 21% in IMID patients (OR 1.21, 95% CI 1.02, 1.43), however, this association was attenuated after adjustment for demographics and comorbidities (OR 1.08). Table 1. Risk Factors for COVID-19 Hospitalizations in IMIDs vs. non-IMIDs Variable OR 95% CI IMIDs vs. Non-IMID 1.23 1.10, 1.37 Age (10 yrs ) 1.49 1.44, 1.54 Sex: Female 0.68 0.62, 0.75 Long term care resident 8.28 7.32, 9.37 ADG: 5-9 vs. 0-4 1.45 1.22, 1.71 10-14 vs. 0-4 2.26 1.92, 2.67 15+ vs. 0-4 3.23 2.73, 3.82 Income (quintile ) Quintile 2 vs. 1 0.82 0.73, 0.93 Quintile 3 vs. 1 0.76 0.67, 0.86 Quintile 4 vs. 1 0.56 0.48, 0.64 Quintile 5 vs. 1 0.46 0.40, 0.54 Urban vs. rural 4.33 3.32, 5.67 ADG - Aggregated Diagnosis Groups Conclusion: Patients with IMID were at higher risk of being hospitalized with COVID-19 and for having complicated hospitalizations. Hospitalization risk was partially independent of their comorbid conditions. Acknowledgements: The study is supported by ICES, which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). Parts of this material are based on data and information compiled and provided by MOHLTC and the Canadian Institute for Health Information. The opinions, results and conclusions reported in this paper are those of the authors and are independent of the funding or data sources; no endorsement is intended or should be inferred. Disclosure of Interests: None declared