Variable | Univariable model | Multivariable model* | ||||||
HR | Lower 95% CI | Upper 95% CI | P value | HR | Lower 95% CI | Upper 95% CI | P value | |
Age | ||||||||
<18 years | 0.17 | 0.09 | 0.34 | <0.001 | 0.14 | 0.07 | 0.27 | <0.001 |
18–29 years | 0.35 | 0.26 | 0.47 | <0.001 | 0.29 | 0.21 | 0.39 | <0.001 |
30–49 years | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
50–64 years | 3.04 | 2.63 | 3.51 | <0.001 | 4.05 | 3.48 | 4.71 | <0.001 |
≥65 years | 11.09 | 9.73 | 12.64 | <0.001 | 15.46 | 13.28 | 17.99 | <0.001 |
Sex | ||||||||
Men | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Women | 0.68 | 0.63 | 0.73 | <0.001 | 1.02 | 0.95 | 1.09 | 0.661 |
Country | ||||||||
Denmark | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Finland | 0.81 | 0.74 | 0.90 | <0.001 | 0.70 | 0.63 | 0.78 | <0.001 |
Sweden | 0.96 | 0.89 | 1.05 | 0.361 | 0.92 | 0.84 | 1.00 | 0.048 |
Calendar year (per year) | 1.01 | 1.00 | 1.02 | 0.001 | 0.97 | 0.96 | 0.98 | <0.001 |
Disease duration (per year) | 0.98 | 0.98 | 0.99 | <0.001 | 1.07 | 1.07 | 1.08 | <0.001 |
Comorbidities†‡ | ||||||||
Autoimmune disease | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 1.53 | 1.40 | 1.66 | <0.001 | 1.00 | 0.91 | 1.10 | 0.993 |
Diseases of the blood and blood-forming organs | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 3.16 | 2.88 | 3.46 | <0.001 | 1.65 | 1.49 | 1.82 | <0.001 |
Diseases of the circulatory system | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 2.77 | 2.58 | 2.96 | <0.001 | 1.25 | 1.15 | 1.36 | <0.001 |
Diseases of the eye and adnexa | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 2.97 | 2.76 | 3.20 | <0.001 | 1.06 | 0.97 | 1.17 | 0.193 |
Diseases of the musculoskeletal system and connective tissue | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 2.43 | 2.17 | 2.73 | <0.001 | 1.05 | 0.96 | 1.13 | 0.293 |
Diseases of the respiratory system | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 1.97 | 1.78 | 2.19 | <0.001 | 1.59 | 1.40 | 1.80 | <0.001 |
Endocrine, nutritional and metabolic diseases | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 2.03 | 1.87 | 2.20 | <0.001 | 1.65 | 1.51 | 1.79 | <0.001 |
Mental and behavioural disorders | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 1.37 | 1.21 | 1.55 | <0.001 | 1.28 | 1.14 | 1.45 | <0.001 |
Neoplasms—except thymoma | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 2.83 | 2.62 | 3.07 | <0.001 | 1.33 | 1.19 | 1.48 | <0.001 |
Neoplasms—thymoma | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 1.02 | 0.78 | 1.34 | 0.887 | 1.87 | 1.65 | 2.12 | <0.001 |
Severe infections | ||||||||
No | 1.00 | – | – | Reference | 1.00 | – | – | Reference |
Yes | 3.81 | 3.39 | 4.28 | <0.001 | 1.03 | 0.78 | 1.36 | 0.826 |
*Mutually adjusted.
†Comorbidities included as a time-varying covariate.
‡Comorbidities were grouped into: autoimmune disease (hypothyroidism, rheumatoid arthritis, type 1 diabetes mellitus, hyperthyroidism, psoriasis, polymyalgia rheumatica, ulcerative colitis, psoriatic arthritis, multiple sclerosis, Crohn’s disease, coeliac disease, systemic lupus erythematosus, Henoch-Schoenlein purpura (IgA vasculitis), primary sclerosing cholangitis and ankylosis spondylitis); diseases of the blood and blood-forming organs (anaemia, thrombocytopenia and lymphopenia); diseases of the circulatory system (hypertension, stroke, myocardial infarction, cardiac arrhythmia and pulmonary embolism); diseases of the eye and adnexa (cataract and glaucoma); diseases of the musculoskeletal system and connective tissue (osteoporosis); diseases of the respiratory system (asthma and chronic obstructive lung disease); endocrine, nutritional and metabolic diseases (type 2 diabetes mellitus, dyslipidaemia, obesity and diabetes—other than types 1 and 2); mental and behavioural disorders (depression, anxiety disorders and mood disorders); neoplasms—except thymoma; neoplasms—thymoma; and severe infections (systemic infections and aseptic meningitis).