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Stat Med. 1991 Apr;10(4):577-81.

Channeling bias in the interpretation of drug effects.

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Department of Epidemiology, University of Limburg, Maastricht, The Netherlands.


Channeling is a form of allocation bias, where drugs with similar therapeutic indications are prescribed to groups of patients with prognostic differences. Claimed advantages of a new drug may channel it to patients with special pre-existing morbidity, with the consequence that disease states can be incorrectly attributed to use of the drug. For the study of adverse drug reactions, large databases supply information on co-medication and morbidity of patients. For diseases with a stepped-care approach, the drug history of patients, as available from some databases, can show channeling of drugs to patients with markers of relatively severe disease.

[Indexed for MEDLINE]

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