Table 3

Cox proportional hazards model examining the HR of death and 95% CIs among patients with myasthenia gravis in Denmark, Finland and Sweden in relation to explanatory variables in 2000–2020 (prevalent subcohort)

VariableUnivariable modelMultivariable model*
HRLower 95% CIUpper 95% CIP valueHRLower 95% CIUpper 95% CIP value
Age
 <18 years0.170.090.34<0.0010.140.070.27<0.001
 18–29 years0.350.260.47<0.0010.290.210.39<0.001
 30–49 years1.00Reference1.00Reference
 50–64 years3.042.633.51<0.0014.053.484.71<0.001
 ≥65 years11.099.7312.64<0.00115.4613.2817.99<0.001
Sex
 Men1.00Reference1.00Reference
 Women0.680.630.73<0.0011.020.951.090.661
Country
 Denmark1.00Reference1.00Reference
 Finland0.810.740.90<0.0010.700.630.78<0.001
 Sweden0.960.891.050.3610.920.841.000.048
Calendar year (per year)1.011.001.020.0010.970.960.98<0.001
Disease duration (per year)0.980.980.99<0.0011.071.071.08<0.001
Comorbidities†‡
Autoimmune disease
 No1.00Reference1.00Reference
 Yes1.531.401.66<0.0011.000.911.100.993
Diseases of the blood and blood-forming organs
 No1.00Reference1.00Reference
 Yes3.162.883.46<0.0011.651.491.82<0.001
Diseases of the circulatory system
 No1.00Reference1.00Reference
 Yes2.772.582.96<0.0011.251.151.36<0.001
Diseases of the eye and adnexa
 No1.00Reference1.00Reference
 Yes2.972.763.20<0.0011.060.971.170.193
Diseases of the musculoskeletal system and connective tissue
 No1.00Reference1.00Reference
 Yes2.432.172.73<0.0011.050.961.130.293
Diseases of the respiratory system
 No1.00Reference1.00Reference
 Yes1.971.782.19<0.0011.591.401.80<0.001
Endocrine, nutritional and metabolic diseases
 No1.00Reference1.00Reference
 Yes2.031.872.20<0.0011.651.511.79<0.001
Mental and behavioural disorders
 No1.00Reference1.00Reference
 Yes1.371.211.55<0.0011.281.141.45<0.001
Neoplasms—except thymoma
 No1.00Reference1.00Reference
 Yes2.832.623.07<0.0011.331.191.48<0.001
Neoplasms—thymoma
 No1.00Reference1.00Reference
 Yes1.020.781.340.8871.871.652.12<0.001
Severe infections
 No1.00Reference1.00Reference
 Yes3.813.394.28<0.0011.030.781.360.826
  • *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).