This is both the most difficult area to research and the most important. Doctors may not be aware of how much promotion they are exposed to. Therefore, as much as possible, research on the effect of promotion on behaviour should avoid relying on self-report data to show causal relationships. Self-report data are appropriate for finding out what people think is happening, or how they want to present themselves to others, but in this area, that may be far from the reality.
This review looks at the evidence for several different possible effects of promotion on behaviour. These are the impact of promotion on individual prescribing behaviour, on overall drug sales, and on requests for formulary additions; the effect of DTCA on consumers’ decisions, the effect of promotion on the content of continuing medical education courses, and the impact of industry funding on research outcomes.