IIM subgroup frequencies by country
| Polymyositis | Dermatomyositis | Overlap | Total | |
|---|---|---|---|---|
| n (%) | n (%) | n (%) | n (%) | |
| Hungary | 101 (56) | 42 (23)* | 38 (21)† | 181 |
| Czech Republic | 82 (45) | 95 (52)‡ | 6 (3)§ | 183 |
| Sweden | 53 (56) | 37 (39) | 4 (4) | 94 |
| UK | 40 (40) | 39 (39) | 20 (20) | 99 |
| Total | 276 (50) | 213 (38) | 68 (12) | 557 |
Comparing country with data from other countries combined: *Hungary: dermatomyositis versus polymyositis plus overlap: OR 0.36, 95% CI 0.24 to 0.54, corrected probability pcorr<0.0001; †Hungary: overlap versus polymyositis plus dermatomyositis: OR 3.06, 95% CI 1.83 to 5.14, pcorr<0.0001; ‡Czech Republic: dermatomyositis versus polymyositis plus overlap: OR 2.34, 95% CI 1.63 to 3.37, pcorr<0.0001; §Czech Republic: overlap versus polymyositis plus dermatomyositis: 0.17, 95% CI 0.07 to 0.40, pcorr<0.0001.
IIM, idiopathic inflammatory myopathy.