Comparison of Risk Factors During First and Second Wave of COVID-19 in Patients with Autoimmune Rheumatic Diseases (AIRD): Results from KRACC Subset.

Background: The differential influence and outcome of various risk factors on occurrence of COVID-19 among patients with autoimmune rheumatic diseases (AIRD) during different COVID-19 peaks is underreported.

Aim: To assess the impact and outcome of conventional risk factors, immunosuppressants, and comorbidities on the risk of COVID-19 among AIRD patients during the first two COVID-19 peaks.

Design: Prospective, non-interventional longitudinal cohort study.

Methods: This is a subset of the KRA COVID19 cohort undertaken during the initial wave of COVID-19 (W1) (Apr-Dec2021); and the 2nd-wave (W2) (Jan-Aug2021). Data collected included description of AIRD subsets, treatment characteristics, comorbidities, and COVID-19 occurrence. Risk factors associated with mortality were analysed. The incidence rate was compared with that of the general population in the same geographic region.

Results: AIRD patients (n=2969) had a higher incidence of COVID-19 in the W2 (7.1%) than in the W1 (1.7%) as compared to the general population (Government bulletin). Age (p<0.01) and duration of AIRD (p<0.001) influenced COVID-19 occurrence in W2 while major disease subsets and immunosuppressants including glucocorticoids did not. The W2 had lower HCQ usage (Adjusted Odds Ratio [AOR]-0.81) and comorbidities like hypertension (AOR -0.54) and pre-existing lung disease (AOR -0.38;0.19-0.75) compared to W1. Older age (1.11) and coexistent diabetes mellitus (AOR 6.74) were independent risk factors associated with mortality in W2.

Conclusions: We report 1.7 times higher occurrence, and no influence of major disease subsets or immunosuppressants including glucocorticoids on COVID-19. Age and diabetes were independent risk factors for mortality.