Table A4. GRADE Evidence Profile for Comparison of B Vitamins Versus Placebo.
| No. of Studies (Design) | Risk of Bias | Inconsistency | Indirectness | Imprecision | Publication Bias | Upgrade Considerations | Quality |
|---|---|---|---|---|---|---|---|
| Cognitive function | |||||||
| 4 systematic reviews (including 17 RCTs) | No serious limitations | No serious limitations | Serious limitations (-1)a | No serious limitations | Undetected | None | ⊕⊕⊕ Moderate |
| Rate of brain atrophy per year | |||||||
| 1 RCT (VITACOG) | No serious limitations | Consistency unknown (single study) | Serious limitations (-1)b | No serious limitations | Undetected | None | ⊕⊕ Low-Moderate |
a
None of the RCTs identified included the population of interest (i.e., patients with dementia or cognitive impairment and vitamin B12 deficiency).
b
Rate of brain atrophy is an indirect measure of disease progression and cognitive function. Abbreviation: RCT, randomized controlled trial.