Sensitivity analyses A separate analysis was performed for probable and for possible click here MG patients. Results Table 1 shows that there were 1,066 incident patients with probable or possible MG matched to 6,392 controls identified between 1987 and 2009. The mean age of patients with MG was 62 years and 50 % were female. Most patients with incident MG (78 %) were able to be classified with probable MG. Patients were followed for a median of 4 years.

Table 1 Baseline characteristics of patients with incident myasthenia gravis and control patients   MG patients Controls Probable MG patients Possible MG patients Characteristics (n = 1,066) (n = 6,392) (n = 834) (n = 232) Female 49.7 49.8 45.6 64.7 Mean age (years) 61.6 61.4 62.4 58.4 BMI (%)  <20 5.2 5.5 4.3 8.2  >30 21.5 16.6 22.9 16.4  Unknown 13.0 15.5 12.6 14.7 Smoking status (%)  Never 47.7 43.2 46.6 51.7  Current 13.8 17.6 13.5 14.7  Ex 23.2 22.0 25.5 14.7  Unknown 15.3 17.1 14.3 19.0 Alcohol status (%)  Never 14.7 10.4 15.2 12.9  Current 57.5 59.6 57.6 57.3  Ex 5.5 3.9 6.0 3.9  Unknown 22.2 26.1 21.2 25.9 Fracture history (%)  Any fracture 15.1 15.7 15.0 15.5  Fracture at osteoporotic sites 6.8 7.5 6.7 6.9  Hip fracture 0.8 0.6 0.8 0.4  Vertebral fracture 0.8 0.6 0.5 0.9  Radius/ulna find more fracture 2.8 3.9 2.6 3.4 Comorbidity ever before index

date (%)  Asthma 13.1 10.5 12.8 14.2  COPD 3.0 4.2 3.1 2.6  Congestive heart failure 2.3 2.9 2.0 3.4  Diabetes mellitus 7.9 6.9 8.8 4.7  Rheumatoid arthritis 2.6 1.3 2.8 2.2  Renal failure 1.1 0.9 1.2 0.9  Cerebrovascular disease 8.0 6.1 8.8 5.2  Inflammatory bowel disease 0.8 0.8 0.7 1.3  Cancer 18.3 18.1 18.6 17.2  Thyroid disorders 18.7 11.0 18.0 21.1  Secondary osteoporosis 6.6 4.5 6.5 6.9 Drug use in 6 months before index date (%)  Pyridostigmine 13.0 0.0 16.5 0.4  Oral glucocorticoids 8.7 2.8 9.2 6.9  Immunosuppressantsa 2.2 0.4 2.8 0.0  Antidepressants 10.4 8.4 Org 27569 10.9 8.6  Antipsychotics 1.2 1.3 1.2 1.3  Anxiolytics 8.4 5.9 7.4 12.1  Anticonvulsants 3.3 1.8 3.2 3.4  Bisphosphonates 4.1 1.8 4.2 3.9  Hormone replacement therapy 1.9 1.7 1.6 3.0 aCiclosporin, azathioprine, tacrolimus, mycophenolate mofetil and methotrexate are included When compared with their matched controls, patients with a diagnosis of MG had no increased risk of either all fractures in both unadjusted and adjusted models (adjusted hazard ratio (AHR) for any fracture 1.11 (95 % confidence interval [CI] 0.84–1.47) or typical osteoporotic fractures AHR 0.98 (95 % CI 0.67–1.41); Table 2.