Table 3. Odds ratios (95% CI) for childhood leukaemia by exposure level with adjustment for age, sex and SES.
| Type of study | 0.1–<0.2 μT | 0.2–<0.3 μT | ⩾0.3 μT | Oa | Ea |
|---|---|---|---|---|---|
| Measurement studies | |||||
| Brazil | 0.89 (0.54–1.47) | 0.97 (0.43–2.19) | 1.26 (0.61–2.62) | 11 | 9.3 |
| Germany | 1.02 (0.66–1.59) | 1.32 (0.49–3.54) | 3.05 (0.68–13.8) | 4 | 1.2 |
| Japan | 1.10 (0.59–2.04) | 1.50 (0.58–3.88) | 1.40 (0.56–3.49) | 8 | 6.2 |
| Calculated field studies | |||||
| Italy1 | 2.36 (0.55–10.1) | 0 cases/1 controls | 0 cases/1 controls | 0 | 0.2 |
| Italy2 | 0 cases/1 controls | 0 cases/0 controls | 2.26 (0.20–25.9) | 1 | 0.4 |
| UK | 2.01 (0.50–8.03) | 0 cases/1 controls | 0.98 (0.14–6.97) | 2 | 1.9 |
| Summary b | |||||
| Measurement studies | 1.00 (0.74–1.33) | 1.19 (0.71–1.99) | 1.49 (0.88–2.51) | 23 | 16.6 |
| Calculated field studies | 2.02 (0.75–5.41) | 0 cases/2 controls | 1.15 (0.25–5.32) | 3 | 2.7 |
| All studies | 1.07 (0.81–1.41) | 1.16 (0.69–1.93) | 1.44 (0.88–2.36) | 26 | 18.9 |
| All without Brazil | 1.16 (0.83–1.61) | 1.30 (0.67–2.54) | 1.56 (0.78–3.10) | 15 | 9.9 |
Abbreviations: CI=confidence interval; SES=socioeconomic status.
Reference level: <0.1 μT.
a
Observed (O) and expected (E) number of cases ⩾0.3 μT, with expected numbers obtained by modelling probability of membership in exposure categories based on the distribution of controls including covariates.
b
Adjusted for study, age, sex and SES.