Healthy Skepticism Library item: 10601

Warning: This library includes all items relevant to health product marketing that we are aware of regardless of quality. Often we do not agree with all or part of the contents.

Publication type: news

Non Sequitur
Prescribing Advice for GPs: An NHS Prescribing Advisers’ Blog 2007 Jun 20
http://www.prescriber.org.uk/?p=386

Full text:

Non sequitur, translated from Latin to English, means “it does not follow”. Non sequiturs are often used in advertising both overtly and covertly.

An example of an overt use would be placing two statements next to each other so that the reader correlates the two statements despite no correlation existing. For example:

Drug X exhibits high affinity for the target receptor
Drug X has no known side effects
While these two statements may be factually correct they are not related to each other and there is no cause and effect. Despite this, on first reading, you may have been inclined to believe that Drug X had no side effects because it has a high affinity for the target receptor.

A more covert use of non sequiturs is to involve pictorial or graphical representations. For example, many adverts depict tropical or exotic locations or idealistic situations. These locations and situations often have no direct link with product being advertised.

Action: Clinicians should be aware of the potential influence of non sequiturs in advertising. Careful analysis of promotional materials will ensure that incorrect conclusions are not formed based on unrelated statements.