Table 5.
Certainty of evidence by GRADE criteria
| CVD | CHD | Stroke | Heart failure | |
|---|---|---|---|---|
| No. of studies | 17 (14) | 24 (16) | 22 (16) | 6 (4) |
| Downgrade quality of evidence | ||||
| Risk of bias | No | No | No | No |
| Inconsistency | Yes | Yes | No | No |
| Indirectness | No | No | No | Yes |
| Imprecision | No | No | No | No |
| Publication Bias | No | No | No | No |
| Upgrade quality of evidence | ||||
| Large effect | No | No | No | No |
| Plausible confounding | Noa | Noa | No | No |
| Dose–response | Yesb | No | Yesb | Yesb |
| Overall quality of evidence | Low | Low | Moderate | Low |
aDespite better quality studies provided less heterogeneity across results
bThe analyses showed no evidence for non-linearity of associations