TABLE 1.
Rates of immune thrombocytopenia per 100,000 population
| Age group | 1980 | 1981 | 1982 | 1983 | 1984 | 1985 | 1986 | 1987 |
|---|---|---|---|---|---|---|---|---|
| 0 to 9 | 3.8 | 1.5 | 3.8 | 6.8 | 4.5 | 4.5 | 3.7 | 2.9 |
| 10 to 19 | 0.6 | 1.3 | 3.2 | 1.3 | 1.4 | 2.1 | 2.1 | 4.3 |
| 20 to 29 | 1.3 | 1.9 | 2.5 | 1.2 | 4.3* | 3.7* | 3.6* | 4.8* |
| 30 to 39 | 0.0 | 1.6 | 0.0 | 0.7 | 3.6* | 4.8* | 3.3* | 1.3* |
| 40 to 49 | 2.4 | 0.0 | 2.3 | 2.2 | 1.1 | 0.0 | 3.1 | 1.0 |
| > 49 | 3.4 | 3.4 | 4.8 | 4.8 | 3.8 | 3.3 | 5.1 | 4.2 |
| Mean | 2.0 | 1.9 | 3.0 | 3.1 | 3.3 | 3.5 | 3.7 | 3.3 |
*
Rates significantly different from previous four years (P=0.002) (χ2 test for trend = 2.9 (confidence interval 1.4 to 6.0)