Table 2.
Effect of calcium supplementation on blood lead concentration (log-transformed) (n = 557; intent-to-treat analysis).
| Variable | β-Coefficient | p-Value | 95% CI |
|---|---|---|---|
| Treatment (calcium = 1; placebo = 0) | −0.117 | 0.004 | (−0.196 to −0.038) |
| Blood lead at baseline (μg/dL)a | 0.674 | < 0.001 | (0.165 to 0.732) |
| Age (years) | 0.007 | 0.051 | (−0.00003 to 0.014) |
| Dietary calcium intake at baseline (g/day) | −0.024 | 0.751 | (−0.169 to 0.122) |
| Total energy intake at baseline (1,000 kcal/day) | −0.010 | 0.813 | (−0.096 to 0.075) |
| Trimester of pregnancy (time: 1 = third; 0 = second) | 0.119 | < 0.001 | (0.073 to 0.166) |
a
Log-transformed outcome variable, thus estimate of treatment effect: 1 − e−0.117 = −11% (95% CI, −17.8% to −3.7%).