COVID-19 ADMISSIONS and MORTALITY in PATIENTS with EARLY INFLAMMATORY ARTHRITIS: RESULTS from A NATIONAL COHORT

ABSTRACT

Background: There has been a major concern about the impact of COVID-19 in patients with infammatory arthritis during the pandemic, with recommendations from governments for patients to shield. Objectives: Our aim was to describe the risk factors for COVID-19 hospitalisation and mortality amongst patients recruited to the National Early Infammatory Arthritis Audit (NEIAA) in England. Methods: An observational cohort study design was used. The population included adults in England with new diagnoses of infammatory arthritis between May 2018 and March 2021 who enrolled in NEIAA. The outcomes were hospitalisation due to COVID-19 (primary admission reason or nosocomial acquisition) and death due to COVID-19 (COVID-19 stated on a death certifcate), identifed via linkage with secondary care records. Hazard ratios were calculated using Cox proportional hazards models, with adjustment for patient factors (age, gender, smoking status, and comorbidity) and disease factors (seropositivity, 28-joint disease activity score, patient-reported disability (HAQ), and functional impact (MSK-HQ)) recorded at baseline. Individuals were considered at risk from the date of diagnosis or February 2020 (whichever was later) and censored at a COVID-19 event, death or May 2021 (whichever was sooner). Results: 14,127 patients were included. The mean age was 57 years;62% were female;19% were current smokers, while 29% were ex-smokers. The frequency of comorbidities at baseline were hypertension (19%), diabetes mellitus (9%), and lung disease (9%). Overall, 20% had two or more comorbidities. Rheumatoid factor or CCP antibodies were positive in 56%. At presentation, mean scores for DAS28 were 4.6 (+/-1.5), 1. 1 (+/-0.7) for HAQ, and 25 (+/-11) for MSK-HQ. Initial DMARD therapy was known for 13,682/14,127 patients methotrexate was the most common (54%), followed by hydroxychloroquine (23%), and sulfasalazine (11%). There were 143 COVID-19 hospital admissions and 47 deaths, corresponding to incidence rates per 100 person-years for hospitalisation 0.94 [95% CI 0.79-1.10] and death 0.31 [95% CI 0.23-0.41]. Increasing age, male gender, diabetes, hypertension, lung disease and smoking status all predicted COVID-19 hospitalisation and death. Higher baseline DAS28 predicted COVID-19 hospitalisation (HR 1.24 [95% CI 1.10-1.39]) and mortality (HR 1.33 [95% CI 1.09-1.63]). Higher HAQ predicted both COVID-19 hospitalisation and death. Seropositivity was not a signifcant predictor of any COVID-19 event, nor was MSK-HQ. In unadjusted models, corticosteroids associated with COVID-19 death (HR 2.29 [95% CI 1.02-5.13], and sulfasalazine monotherapy associated with COVID-19 hospitalisation (HR 1.93 [95% CI 1.04-3.56]. In adjusted models, associations for corticoster-oids and sulfasalazine were no longer signifcant. Only age, smoking status, and comorbidities independently predicted COVID-19 events. Conclusion: The burden of COVID-19 amongst early arthritis patients was substantial during the pandemic, with concerns about the use of csDMARDs and corticosteroids.1,2 Patient characteristics and rheumatoid disease severity at diagnosis appear to be the more important predictors of COVID-19 events than initial treatment strategy. An important limitation is that we have not looked at treatment changes over time, and must acknowledge that many patients, especially those recruited in 2019, may have changed therapy prior to the pandemic.