Table 3. Hazard ratios of overall cancer incidence and 95% confidence intervals (95% CI) by continuous levels of red blood cell (RBC) folate, serum folate, and dietary folate equivalents (DFE) 1, NHANES 1999–2002.
| Hazard ratio (95% CI)2 | Coefficient | P | |
|---|---|---|---|
| RBC folate (ng/ml) | 0.57 (0.40–0.81) | -0.57 | < 0.01 |
| Serum folate (ng/ml) | 0.51(0.32–0.80) | -0.68 | < 0.01 |
| DFE (μg/d) | 0.81(0.60–1.08) | -0.22 | 0.15 |
1 Tests were performed using Cox proportional hazards regression models that included log-transformed RBC folate, serum folate or DFE as independent continuous variables.
2 Models were adjusted for age, gender, race/ethnicity, educational attainment, smoking status, alcohol intake, physical activity, and body mass index. The DFE model was additionally adjusted for total energy intake.