Table 2 Myositis incidence (2004–2008)
Commercial and Medicare supplemental database incidence (per 100,000)1 | Medicaid database incidence (per 100,000)1 | |||||
|---|---|---|---|---|---|---|
Crude rate | Age- and Gender- adjusted rate4 | 95% CI (adjusted rate) | Crude rate | Age- and Gender- adjusted rate4 | 95% CI (adjusted rate) | |
Myositis (Overall) 2 | 4.88 | 4.27 | 4.09-4.44 | 5.20 | 5.23 | 4.74-5.72 |
Dermatomyositis | 1.78 | 1.52 | 1.42-1.63 | 1.72 | 1.70 | 1.42-1.97 |
Polymyositis | 2.83 | 2.46 | 2.33-2.59 | 3.51 | 3.53 | 3.13-3.94 |
Interstitial myositis | 0.79 | 0.73 | 0.66-0.81 | 0.76 | 0.78 | 0.58-0.97 |
Year | ||||||
2004 | 5.37 | 4.52 | 4.07-4.96 | 4.27 | 4.47 | 3.80-5.15 |
2005 | 6.02 | 5.08 | 4.61-5.54 | 6.16 | 6.44 | 5.08-7.80 |
2006 | 5.15 | 4.45 | 4.04-4.86 | 5.33 | 5.14 | 3.73-6.54 |
2007 | 4.80 | 4.25 | 3.87-4.62 | 7.27 | 6.85 | 5.29-8.41 |
2008 | 3.66 | 3.38 | 3.06-3.71 | 5.11 | 5.08 | 3.70-6.45 |
Age | (LRT χ2 =81.73, df = 6 , p < 0.001)3 | (LRT χ2 =38.69, df = 6 , p < 0.001)3 | ||||
18-24 | 1.35 | 1.33 | 0.99-1.67 | 2.02 | 1.74 | 1.09-2.40 |
25-34 | 2.03 | 1.96 | 1.61-2.30 | 3.34 | 3.62 | 2.48-4.76 |
35-44 | 3.14 | 3.10 | 2.74-3.45 | 6.13 | 5.33 | 4.20-6.47 |
45-54 | 4.77 | 4.69 | 4.30-5.08 | 7.97 | 7.54 | 6.12-8.95 |
55-64 | 6.95 | 6.94 | 6.44-7.44 | 10.20 | 9.72 | 7.93-11.52 |
65-74 | 9.25 | 9.30 | 8.38-10.22 | 5.13 | 4.83 | 3.62-6.05 |
75+ | 7.21 | 7.32 | 6.49-8.15 | 3.20 | 3.08 | 2.18-3.99 |
Gender | (LRT χ2 =6.77, df = 1, p =0.009)3 | (LRT χ2 =9.08, df = 1, p =0.003)3 | ||||
Female | 5.97 | 5.38 | 5.11-5.66 | 5.95 | 6.68 | 6.00-7.36 |
Male | 3.65 | 3.07 | 2.85-3.28 | 3.64 | 3.67 | 2.96-4.37 |