Scoring Clinical Evidence
We look at a broad range of medical literature in scoring our Evidence Index, but we don’t give every paper equal weight.
Some studies are better designed and conducted than others.
Some clinical investigators and healthcare institutions are more influential than others.
Some medical journals are more highly regarded than others.
The most reliable clinical findings spring from large, prospective, randomized controlled trials (RCTs) published in
major peer-reviewed journals. The US Food and Drug Administration (FDA) and Undersea and Hyperbaric Medical Society (UHMS)
require RCT evidence for the approval of new clinical indications for hyperbaric oxygen therapy.
The RCT is the gold standard, but not the only standard, for evidence-based medicine (EBM). Randomized controlled trials are
expensive to conduct and take years to complete. In the absence of gold standard RCT evidence, published findings from
well-designed animal research or smaller human clinical trials may persuade some responsible physicians to adopt new
Strong evidence grows stronger as other scientists replicate, refine, and cite the original findings in new published studies.
Weak evidence grows weaker as peers expose weaknesses in study design, data analysis, and professional biases or conflicts
Of course the state of scientific evidence may change instantly, with the publication of a single paper. So our Evidence Index
rating may change the moment we find a new study that meets our criteria. We keep especially alert for findings that refute
previous studies and for papers retracted by their authors or journals.
As a rule HyperbaricLink only recognizes papers listed in
and clinical trials posted on
You can review the medical literature we consulted by following the links to the Sources on our individual diseases and
conditions pages. The links we provide in Clinical Resources will also take you to a wealth of relevant information.