Defined terms in the registry
195 documents of type defined term.
Documents
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The Institute’s judgement of the extent to which an effect estimate is adequate to support a conclusion. Reported at one of four levels: high, moderate, low or very low…
30 Jul 2026 -
The Institute is confident that the true effect lies close to the estimate. Further research is very unlikely to change confidence in the estimate. A high rating is not…
30 Jul 2026 -
The true effect is likely to be close to the estimate, but there is a real possibility that it is substantially different. Further research is likely to have an…
30 Jul 2026 -
Confidence in the effect estimate is limited and the true effect may be substantially different. The Institute states in each case whether the limitation arises from…
30 Jul 2026 -
The Institute has very little confidence in the effect estimate. In this document set a very low rating most often reflects an absence of controlled human evidence…
30 Jul 2026 -
A state in which no study adequate to answer a question has been identified. The Institute records an absence of evidence as distinct from evidence of absence: the first…
30 Jul 2026 -
A finding, from a study adequately powered to detect an effect of the size of interest, that no such effect was observed. A negative result from an adequately powered…
30 Jul 2026 -
The reduction of a certainty rating from its starting level because of a concern in one of five domains: risk of bias, inconsistency, indirectness, imprecision and…
30 Jul 2026 -
The increase of a certainty rating above its starting level, applicable in principle to observational evidence showing a large effect, a dose–response gradient or a…
30 Jul 2026 -
The extent to which features of a study’s design or conduct could produce an effect estimate that systematically departs from the truth. Assessed at the level of the…
30 Jul 2026 -
A mismatch between the population, intervention, comparator or outcome of the contributing studies and those of the question being answered. Also applied where an…
30 Jul 2026 -
A confidence interval wide enough that its ends would support different decisions, or an event count too small to constrain the estimate. Assessed against a decision…
30 Jul 2026 -
Unexplained variation in effect estimates across contributing studies, beyond what chance would produce. Consistency of direction with variation in magnitude is treated…
30 Jul 2026 -
The risk that the studies available to a review are not a representative sample of the studies conducted, most often because studies with unfavourable results were not…
30 Jul 2026 -
The reporting of a subset of measured outcomes chosen after the results were known. Detected by comparing the published report with the registered protocol, which the…
30 Jul 2026 -
A structured table presenting, for each pre-specified outcome, the number of contributing participants and studies, the absolute and relative effect, the certainty…
30 Jul 2026 -
A document answering a structured question by identifying, appraising and combining the studies that bear on it, according to a protocol registered before the search was…
30 Jul 2026 -
A structured map of the evidence available for a question, published where the Institute judges that a quantitative synthesis is not yet supportable. A scoping review…
30 Jul 2026 -
A review whose unit of inclusion is a published systematic review rather than a primary study. Overlap between the included reviews is assessed and reported, because a…
30 Jul 2026 -
The four elements that define a review question: population, intervention, comparator and outcome. The Institute registers a PICO frame before searching and records any…
30 Jul 2026 -
The recording of a review question, eligibility criteria and analysis plan before the search is executed. Registration is what makes a subsequent change identifiable as…
30 Jul 2026 -
The record attached to every Institute synthesis listing each change made after protocol registration, when it was made, and why. A change that is not in the log did not…
30 Jul 2026 -
The assumption, required for indirect comparison, that participants in the contributing trials could in principle have been randomised to any of the compared…
30 Jul 2026 -
An estimate of the difference between two interventions that have not been compared directly, derived through their comparisons with a common comparator. Weaker than a…
30 Jul 2026 -
A synthesis combining direct and indirect comparisons across a connected set of interventions. The Institute publishes network estimates with its transitivity assessment…
30 Jul 2026 -
A repetition of an analysis under a different defensible assumption, conducted to establish whether a conclusion depends on that assumption. Reported whether or not the…
30 Jul 2026 -
An analysis restricted to a subset of participants. Hypothesis-generating unless the subgroup and the interaction test were pre-specified, and the Institute records…
30 Jul 2026 -
A formal test of whether a treatment effect differs across subgroups. A difference in statistical significance between two subgroups is not an interaction test and the…
30 Jul 2026 -
A result in which the observed effect does not differ from the comparator by more than chance would produce. Informative where the study was adequately powered for the…
30 Jul 2026 -
The treatment against which the intervention is compared. An effect estimate is always an estimate against a specific comparator, and no estimate is transferable to a…
30 Jul 2026 -
The effect of an intervention under the conditions of a controlled trial, in a selected population with protocol-driven adherence and follow-up.
30 Jul 2026 -
The effect of an intervention under ordinary conditions of use. Generally smaller than efficacy, principally because adherence and persistence outside a trial are lower.
30 Jul 2026 -
The allocation of participants to study arms by a chance process, which distributes both known and unknown prognostic factors between arms in expectation. The single…
30 Jul 2026 -
The prevention of foreknowledge of the next allocation by the person enrolling a participant. Distinct from blinding, which concerns knowledge after allocation, and…
30 Jul 2026 -
The withholding of knowledge of assignment from participants, investigators, outcome assessors or analysts. The Institute records who was blinded rather than describing…
30 Jul 2026 -
A design in which assignment is known to participants and investigators. Objective endpoint measurement limits but does not eliminate the resulting risk, because…
30 Jul 2026 -
A design in which neither participants nor investigators know the assignment. The Institute records the specific parties blinded, because the term is used inconsistently…
30 Jul 2026 -
A design in which the comparator is an inert preparation matched to the intervention in appearance and administration. Matching is imperfect where the intervention…
30 Jul 2026 -
A design in which the comparator is another active treatment. Establishes a difference between the two treatments and not an effect against no treatment.
30 Jul 2026 -
A design testing whether a treatment is not worse than a comparator by more than a pre-specified margin. A non-inferiority result does not establish superiority over…
30 Jul 2026
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