Table 4.
Pooled Relative Risk of Amyotrophic Lateral Sclerosis by Dietary Vitamin E Intake Among Nonusers of Supplemental Vitamin E in Data From 5 Cohort Studies, 1976–2005
| Quartile of Dietary Vitamin E Intake |
|||||
| 1 (lowest) | 2 | 3 | 4 (highest) | P-trend | |
| No. of cases | 89 | 77 | 93 | 83 | |
| Age-adjusted RR (95% CI)a | 1.00 | 0.72 (0.52, 0.98) | 0.83 (0.62, 1.13) | 0.73 (0.53, 1.01) | 0.19 |
| P value | 0.04 | 0.24 | 0.06 | ||
| P for heterogeneityb | 0.88 | 0.99 | 0.40 | ||
| Multivariate RR (95% CI)c | 1.00 | 0.75 (0.55, 1.04) | 0.87 (0.64, 1.18) | 0.77 (0.56, 1.06) | 0.28 |
| P value | 0.08 | 0.38 | 0.11 | ||
| P for heterogeneityb | 0.83 | 0.99 | 0.40 | ||
Abbreviations: CI, confidence interval; RR, relative risk.
a
Adjusted for age and sex (for analysis of total).
b
P values for the tests of heterogeneity between studies were calculated using the Q statistic.
c
Adjusted for age, smoking status, vitamin C intake, energy intake, body mass index, physical activity, educational level, and sex (for analysis of total).