Table 6
Hazard ratios: cumulative lead exposure
| Cumulative values (μg/dl years) | Relative to external control group (n=236) | Relative to internal control group (n=230) | ||
|---|---|---|---|---|
| Hazard ratio | 95% CI | Hazard ratio | 95% CI | |
| With adjustment only for country | ||||
| <120 (n=124) | 1.31 | (1.02 to 1.68) | 0.93 | (0.74 to 1.17) |
| 120–220 (n=133) | 1.38 | (1.09 to 1.75) | 0.98 | (0.78 to 1.22) |
| 220–420 (n=136) | 1.03 | (0.81 to 1.31) | 0.73 | (0.58 to 0.91) |
| 420+ (n=148) | 1.48 | (1.17 to 1.86) | 1.05 | (0.84 to 1.30) |
| With adjustment for country, mother’s age, smoking, and primiparity | ||||
| <120 (n=124) | 1.28 | (1.00 to 1.65) | 0.94 | (0.73 to 1.18) |
| 120–220 (n=133) | 1.33 | (1.05 to 1.70) | 0.97 | (0.78 to 1.22) |
| 220–420 (n=136) | 0.97 | (0.76 to 1.24) | 0.71 | (0.56 to 0.89) |
| 420+ (n=148) | 1.43 | (1.13 to 1.81) | 1.04 | (0.83 to 1.31) |
