Biases

Here is a list of all Biases in the Catalogue.  Check back regularly as we are adding new ones over time.

 

Admission rate bias

Arises when the variables under study are affected by the selection of hospitalized subjects leading to a bias between the exposure and the disease under study.

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Allocation bias

Systematic difference in how participants are assigned to treatment and comparison groups in a clinical trial.

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Ascertainment bias

Systematic differences in the identification of individuals included in a study or distortion in the collection of data in a study.

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Centripetal bias

The reputations of certain clinicians and institutions cause individuals with specific disorders or exposures to gravitate toward them.

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Chronological bias

When study participants allocated earlier to an intervention or a group are subject to different exposures or are at a different risk from participants who are recruited later.

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Collider bias

A distortion that modifies an association between an exposure and outcome, caused by attempts to control for a common effect of the exposure and outcome.

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Compliance bias

Participants compliant with an intervention differ in some way from those not compliant which can systematically affect the outcome of interest.

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Confounding

A distortion that modifies an association between an exposure and an outcome because a factor is independently associated with the exposure and the outcome.

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Confounding by indication

A distortion that modifies an association between an exposure and an outcome, caused by the presence of an indication for the exposure that is the true cause of the outcome.

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Diagnostic access bias

Individuals differ in their geographic, temporal and economic access to diagnostic procedures which label them as having a given disease.

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