How Evidence Scores Work
NutriVouch calculates Evidence Scores based on the scientific evidence hierarchy. Each score (0–10) reflects how strong the research support is for a substance's effects.
Evidence Hierarchy
Meta-Analysis10 points
Combines results from multiple studies — the gold standard of evidence.
Systematic Review9 points
Comprehensive review of all available studies on a topic.
Randomized Controlled Trial (RCT)7 points
Participants randomly assigned to treatment or control groups.
Cohort Study4 points
Observational study following groups over time.
Case-Control Study3 points
Compares groups with and without a condition.
Scoring Rules
- •Only human studies count — animal and in vitro studies are excluded from scoring.
- •Studies must pass a quality gate: sample size ≥ 20, required fields present.
- •Larger sample sizes (≥ 1000) receive a bonus point.
- •The final score is the weighted average of all qualifying studies, capped at 10.
Score Scale
8.0–10.0Strong evidence
6.0–7.9Moderate evidence
4.0–5.9Limited evidence
0.0–3.9Weak evidence