Reading Evidence Across Systems of Medicine: The IIFM Evidence Labels

Practitioners who work across systems of medicine face a problem that specialists in a single system rarely confront. A patient may be using a guideline recommended medicine, a dietary pattern supported by large trials, a herb studied in a handful of small trials, a traditional practice with centuries of use and no modern research, and a supplement their practitioner recommends on the basis of experience. All 5 may be described to the patient as helpful. They are not supported in the same way, and a practitioner who cannot say so clearly cannot advise the patient well.

IIFM’s evidence labels exist to solve that problem. They are not a replacement for evidence based medicine but a practical way of applying its principles across a wider landscape of care.

What evidence based medicine actually means

Evidence based medicine is sometimes caricatured as medicine by randomised trial alone. Its founders defined it differently: the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients, integrating individual clinical expertise with the best available external evidence. Patient values and preferences were later added explicitly to that definition.

That definition has 3 components that matter for integrated practice. Evidence comes in degrees rather than as present or absent. Clinical judgement is part of the method, not an alternative to it. And the patient’s values shape how evidence is applied.

Grading evidence

The most widely used framework for rating the certainty of evidence is GRADE. It classifies the certainty that an effect is real as high, moderate, low or very low. Randomised trials start as high certainty and observational studies as low, but either can move up or down. Certainty is lowered by risk of bias, inconsistency between studies, indirectness, imprecision and publication bias. It can be raised when effects are very large, when there is a clear dose response relationship, or when plausible biases would have reduced rather than exaggerated the effect.

GRADE also distinguishes the certainty of evidence from the strength of a recommendation. A strong recommendation can rest on moderate evidence when benefits clearly outweigh harms; a weak recommendation may follow from high certainty evidence of a small benefit. This distinction is useful in practice: a low risk intervention with low certainty of benefit may still be reasonable if a patient values it, while a higher risk intervention needs stronger evidence.

The 5 IIFM labels

The label traditional practice deserves particular explanation. Long use is not evidence of effectiveness in the modern sense; practices can persist for centuries without being effective. But it is not nothing either. It may reflect accumulated observation, it often indicates acceptable safety for common uses, and it provides a starting point for research. The artemisinin story, in which a remedy described in a fourth century text led to a Nobel Prize winning malaria treatment, shows the potential. Many other traditional remedies, tested rigorously, have not shown benefit. The label keeps both possibilities open while being honest that the question has not been answered.

Applying the labels: worked examples

2 further points make the labels more useful. First, they apply to a specific claim, not to an intervention in general. Acupuncture may be emerging or evidence supported for some chronic pain conditions and limited for others. Second, labels can change as evidence accumulates, and practitioners should expect to update them.

The biases every practitioner must guard against

Using labels well requires awareness of the biases that distort judgement.

• Confirmation bias: weighing evidence that supports a favoured approach more heavily than evidence against it.
• Anecdote: generalising from memorable individual cases, which are shaped by natural recovery and placebo effects.
• Mechanism as proof: treating a plausible pathway as evidence of clinical benefit.
• Appeal to nature or tradition: assuming that natural or long used means safe or effective.
• Appeal to novelty: assuming that new means better.
• Dismissal by category: rejecting an intervention because of the system it comes from, rather than examining the evidence for it.
• Commercial influence: being swayed by the marketing of tests, products or programmes, particularly when the practitioner has a financial interest.

Communicating evidence to patients

The labels are designed to be explained in plain language. A practitioner might say:

• “There is strong evidence that this helps people in your situation.”
• “The early research is promising, but we do not know yet whether it makes a real difference.”
• “This has been used for a very long time in Ayurveda, but it has not really been studied in modern trials.”
• “This is based on my clinical experience rather than research, so let us try it and see how you respond.”
• “The research so far does not show that this works, although I understand why it appeals.”

Communicating uncertainty honestly tends to increase rather than reduce trust, particularly when paired with a clear plan for how the patient’s response will be monitored.

Labels in documentation and in teams

Recording the evidence basis for recommendations in clinical notes makes reasoning visible to colleagues and to the practitioner’s future self. It also supports coordination: a letter to a patient’s doctor that distinguishes an evidence supported dietary change from a low risk traditional practice the patient values is easier to read and to act on than a list of recommendations without context.

Where the labels fall short

No labelling system captures every nuance. Evidence may be strong for one population and absent for another. A small effect may be well established but unimportant. Harms are sometimes less well studied than benefits. The labels are a starting point for thinking, not a substitute for it, and they work best alongside a careful consideration of safety, relevance and the patient’s own goals.

Why this matters for integration

Integration without an evidence framework slides towards relativism, in which every approach is presented as equally valid. Evidence without integration slides towards dismissal, in which anything outside one system is ignored. The labels allow practitioners to hold both commitments: to take seriously everything a patient uses, and to be honest about how well each part is supported.