Association between autoimmune diseases and COVID-19 as assessed in both a test-negative case–control and population case–control design

Table 2 Un-adjusted and adjusted odds ratios for COVID-19 according to autoimmune disease from case–control designs

Designs	Exposure		OR (95% CI)
Designs	Exposure		Un-adjusted	Adjusted
Test-negative case–control^a	Autoimmune status	No	Referent	Referent
Test-negative case–control^a	Autoimmune status	Yes	0.86 (0.77–0.96)	0.90 (0.80–1.01)
Positive case–control (CC-POS)^a	Autoimmune status	No	Referent	Referent
Positive case–control (CC-POS)^a	Autoimmune status	Yes	1.51 (1.38–1.64)	1.00 (0.92–1.10)
Negative case–control (CC-NEG)^a	Autoimmune status	No	Referent	Referent
Negative case–control (CC-NEG)^a	Autoimmune status	Yes	1.75 (1.62–1.90)	1.15 (1.05–1.25)
Population case–control (case–control design 2)^b	Autoimmune status	No	Referent	Referent
Population case–control (case–control design 2)^b	Autoimmune status	Yes	1.24 (1.13–1.35)	1.16 (1.06–1.26)

^aOdds ratios and corresponding 95% confidence intervals were calculated from a multivariable logistic model adjusted for gender, age (categorized as < 17, [18–40), [40–70), ≥ 70 years), number of non-autoimmune chronic conditions (categorized as no conditions, 1–3, ≥ 4), and municipality of residence (for CC-POS and CC-NEG). Test-positive subjects were matched to test-negatives by ASST and date, date of positive swab for cases and date of negative swab for controls within 7 days of the case index date
^bOdds ratios and corresponding 95% confidence intervals were calculated from a conditional multivariable logistic model adjusted for number of non-autoimmune chronic conditions (categorized as no conditions, 1–3, ≥ 4); cases and controls matched by gender, age and municipality of residence

ISSN: 2038-3274