From: Cancer risks of dermatomyositis and polymyositis: a nationwide cohort study in Taiwan
 | Dermatomyositis group (n = 1,012) | Polymyositis group (n = 643) | ||||
---|---|---|---|---|---|---|
 | Observed | Expected | SIR (95% CI) | Observed | Expected | SIR (95% CI) |
Total | 95 | 18.58 | 5.11 (5.01 to 5.22) | 33 | 15.36 | 2.15 (2.08 to 2.22) |
Age | Â | Â | Â | Â | Â | Â |
   <20 years | 1 | 0.13 | 7.86 (6.26 to 9.36) | 0 | 0.02 | - |
   20 to 39 years | 8 | 1.11 | 7.20 (6.72 to 7.72) | 7 | 0.65 | 10.69 (9.99 to 11.60) |
   40 to 59 years | 55 | 6.67 | 8.25 (8.03 to 8.47) | 13 | 4.98 | 2.61 (2.47 to 2.76) |
   60 to 79 years | 29 | 5.40 | 5.37 (5.18 to 5.57) | 13 | 6.80 | 1.91 (1.81 to 2.02) |
   ≥ 80 years | 2 | 0.24 | 8.47 (7.22 to 9.57) | 0 | 0.52 | - |
Gender | Â | Â | Â | Â | Â | Â |
   Male | 39 | 7.16 | 5.44 (5.28 to 5.62) | 12 | 6.51 | 1.84 (1.74 to 1.95) |
   Female | 56 | 10.99 | 5.10 (4.96 to 5.23) | 21 | 8.89 | 2.36 (2.26 to 2.47) |
Follow-up | Â | Â | Â | Â | Â | Â |
   <1 years | 64 | 3.00 | 21.30 (20.81 to 21.86) | 18 | 2.67 | 6.75 (6.43 to 7.06) |
   1 to 2 years | 12 | 2.36 | 5.08 (4.80 to 5.38) | 3 | 2.30 | 1.31 (1.16 to 1.46) |
   2 to 5 years | 13 | 5.16 | 2.52 (2.38 to 2.66) | 5 | 4.93 | 1.01 (0.93 to 1.11) |
   >5 years | 6 | 4.39 | 1.37 (1.26 to 1.48) | 7 | 3.51 | 1.99 (1.85 to 2.15) |