Table 4.
Person-years (PY) of follow-up and standardized incidence ratios (SIR) of solid tumor and leukemia SMNs according to various study factors (observed/expected = SIR)
| Factor | Level | PY | Solid tumors | p* | Leukemias | p |
|---|---|---|---|---|---|---|
| Gender | Male | 81,282 | 81/14.8=5.5 | 0.435 | 15/3=4.9 | 0.970 |
| Female | 88,359 | 93/19.1=4.9 | 13/2.6=5.0 | |||
| Decade | 1960–1969 | 12,173 | 25/5.1=4.9 | 0.187 | 0/0.3=0.0 | 0.026 |
| of WT | 1970–1979 | 53,817 | 88/14.6=6.0 | (0.142) | 5/1.5=3.2 | (0.003) |
| 1980–1989 | 63,808 | 47/10.2=4.6 | 6/2.1=2.9 | |||
| 1990–2003 | 39,843 | 14/4=3.5 | 17/1.7=9.9 | |||
| Age at | 0–4 | 132,016 | 109/24.2=4.5 | 0.013 | 20/4.7=4.3 | 0.126 |
| WT (yrs) | 5–14 | 37,624 | 65/9.8=6.7 | 8/1=8.1 | ||
| Attained | 0–9 | 64,538 | 17/5.5=3.1 | 0.108 | 16/3.1=5.1 | 0.823 |
| age (yrs) | 10–19 | 66,260 | 52/8.5=6.1 | (0.208) | 10/1.6=6.2 | (0.349) |
| 20–29 | 30,483 | 64/12.3=5.2 | 2/0.7=3.0 | |||
| 30+ | 8,360 | 41/7.6=5.4 | 0/0.2=0.0 | |||
| Time | 0–9 | 92,923 | 38/8.5=4.5 | 0.264 | 24/3.8=6.3 | 0.308 |
| since | 10–19 | 52,802 | 68/10.9=6.2 | (0.957) | 2/1.2=1.6 | (0.100) |
| WT (yrs) | 20–29 | 20,224 | 49/10.7=4.6 | 2/0.5=4.2 | ||
| 30+ | 3,692 | 19/3.7=5.1 | 0/0.1=0.0 | |||
| Cohort | N. America | 112,975 | 104/20.8=5.0 | 0.747 | 24/3.9=6.2 | 0.586 |
| Britain | 36,417 | 41/8.2=5.0 | 4/1.1=3.5 | |||
| Nordic | 20,249 | 29/5=5.8 | 0/0.7=0.0 |
*
p-values in parentheses are for trend with ordered category