Outcome of interest | No. of studies | OR (95Â % CI) | p heterogenity | I 2 (%) | p for interaction |
---|---|---|---|---|---|
Total dietary fiber | 17 | 0.89 (0.77, 1.01) | 0.005 | 53.6 | Â |
Study design | |||||
 Cohort | 5 | 0.94 (0.77, 1.11) | 0.004 | 74.3 | 0.202 |
 Case-control | 12 | 0.82 (0.68, 0.96) | 0.277 | 17.0 |  |
Study quality | |||||
 Low | 8 | 0.73 (0.56, 0.90) | 0.335 | 12.2 | 0.033 |
 High | 9 | 0.96 (0.83, 1.08) | 0.04 | 51.7 |  |
Geographical region | |||||
 Europe | 7 | 0.90 (0.71, 1.09) | 0.01 | 63.5 | 0.937 |
 North America | 6 | 0.90 (0.64, 1.16) | 0.059 | 53.1 |  |
 Japan | 2 | 0.95 (0.72, 1.17) | 0.41 | 0 |  |
Assessment | |||||
 Interview | 11 | 0.94 (0.79, 1.10) | 0.313 | 13.8 | 0.931 |
 Questionnaire | 4 | 0.93 (0.76, 1.09) | 0.02 | 69.7 |  |
Family history | Â | Â | Â | Â | Â |
 Yes | 8 | 0.84 (0.62, 1.05) | 0.002 | 69.4 | 0.44 |
 No | 9 | 0.94 (0.81, 1.08) | 0.187 | 29.0 |  |
BMI | |||||
 Yes | 8 | 0.87 (0.66, 1.08) | 0.001 | 70.3 | 0.695 |
 No | 9 | 0.92 (0.79, 1.06) | 0.21 | 26.4 |  |
Energy intake | |||||
 Yes | 14 | 0.91 (0.78, 1.04) | 0.007 | 55.1 | 0.507 |
 No | 3 | 0.81 (0.54, 1.07) | 0.14 | 49.2 |  |
Multiple confoundersa | |||||
 Yes | 6 | 0.82 (0.54, 1.09) | 0.306 | 14.4 | 0.387 |
 No | 11 | 0.95 (0.84, 1.05) | <0.001 | 77.7 |  |
Tumor stage | |||||
 Local | 3 | 0.98 (0.89, 1.08) | 0.24 | 30.5 | 0.562 |
 Advanced | 4 | 0.93 (0.79, 1.07) | 0.24 | 29.3 |  |
Source of intake | |||||
 Cereal fiber | 3 | 1.05 (0.94, 1.16) | 0.52 | 0 | 0.02 |
 Fruit fiber | 3 | 0.92 (0.81, 1.03) | 0.55 | 0 |  |
 Vegetable fiber | 3 | 0.87 (0.53, 1.21) | 0.001 | 84.8 |  |
 Legume fiber | 1 | 0.55 (0.32, 0.95) | NA | NA |  |
Solubility | |||||
 Soluble fiber | 2 | 0.87 (0.52, 1.22) | 0.13 | 57.2 | 0.777 |
 Insoluble fiber | 3 | 0.80 (0.46, 1.13) | 0.005 | 81.0 |  |