How we rate evidence
Tinnitus attracts an unusual amount of confident marketing built on very thin research. This page explains the scale we use to tell the two apart, so you can check our reasoning rather than take our word for it.
This is our scale, not an official one
The Tinnitus Clarified Evidence Rating is our own framework. It is informed by how established systems like GRADE think about certainty, but it is not GRADE, it is not a guideline body’s rating, and no professional organisation endorses it. We label it by name everywhere it appears precisely so it cannot be mistaken for one.
What it is for: letting you see, in one glance, whether a treatment rests on consistent high-quality research or on a single small study — a distinction marketing copy works hard to blur.
The grades
A — Strong
Consistent findings from high-quality systematic reviews, clinical guidelines, or several well-conducted controlled trials.
What it does not mean: That it works for everyone, or that it will work for you. Strong evidence describes averages across groups, not individual outcomes.
B — Moderate
Reasonable supporting evidence, with limitations that matter — smaller trials, shorter follow-up, or inconsistency between studies.
What it does not mean: That the effect is established. Further research could meaningfully change this picture.
C — Limited
Small studies, inconsistent results, or methodological weaknesses that make the findings hard to rely on.
What it does not mean: That it does not work — only that the evidence available cannot currently show whether it does.
D — Preliminary
Early-stage or exploratory research, often without controlled human trials yet.
What it does not mean: That it is a treatment option. Preliminary research frequently does not replicate.
E — Insufficient
Too little evidence exists to draw any meaningful conclusion in either direction.
What it does not mean: That it is useless, or that it is promising. It means the question is genuinely open.
F — Evidence against
Available evidence suggests no benefit, or that potential harms outweigh benefits.
What it does not mean: That it is dangerous in every case. Read the specific evidence rather than treating the grade as a verdict.
Which sources carry more weight
Not all evidence is equivalent, and presenting it as though it were is the most common way health content misleads without stating anything factually false. We weight sources roughly in this order:
| Tier 1 | Clinical guidelines, systematic reviews, meta-analyses, well-conducted randomised controlled trials |
| Tier 2 | Large cohort and prospective studies |
| Tier 3 | Smaller clinical studies |
| Tier 4 | Mechanistic and animal studies |
| Tier 5 | Expert opinion and clinical experience |
| Tier 6 | Media coverage, press releases, manufacturer claims |
A mechanistic study showing a plausible pathway is genuinely interesting, and genuinely not the same as a trial showing that people got better. Where we cite lower-tier evidence, we say so in the text rather than letting it sit unqualified alongside stronger findings.
What the ratings deliberately do not do
- They do not predict your outcome. Evidence describes what happened to groups of people in studies. Tinnitus varies enormously between individuals, and a strong average effect is entirely compatible with no effect for you.
- They do not rank treatments against each other. Two treatments can both be rated B while targeting completely different things — one reducing distress, the other affecting perceived loudness.
- They are not medical advice. A rating summarises research. It is not a recommendation about what you should do.
- They are not permanent. Evidence moves. Where a rating changes, the change is recorded on our corrections page.
Telling us we got it wrong
If a rating looks wrong, or a source does not support the claim attached to it, tell us which article and what specifically is wrong through the contact form. Those get checked, and where we got it wrong the article is corrected and the change is logged publicly.