Evidence Grading System
How strategies are evaluated and ranked.
Tier A — Strong Evidence
- Multiple randomized controlled trials (RCTs)
- Meta-analyses or systematic reviews
- Large observational studies (n > 1,000)
- Consistent results across populations
- Established clinical guidelines recommend
Tier B — Moderate Evidence
- Single well-designed RCT
- Cohort studies with consistent results
- Smaller observational studies (n = 100-1,000)
- Plausible mechanism with clinical support
Tier C — Preliminary Evidence
- Pilot studies or small trials
- Case series (n < 100)
- Strong mechanistic evidence
- Expert consensus without RCT support
Tier D — Emerging Evidence
- Theoretical or mechanistic rationale only
- Anecdotal reports
- Expert opinion
- Promising but unproven
Cost Ratings
- $ — Free or very low cost
- $$ — Moderate cost, accessible
- $$$ — Higher cost, may need specialist
- $$$$ — Expensive, limited accessibility