Table 1 The Red Pills

Imagine an initial trial of a drug to reduce the likelihood of acute stroke in high-risk patients, where the drug is described as "the red pill" rather than in terms of its pharmacological properties. Over two to three years the "red pill" produces positive outcomes across a range of randomised controlled trials of patients at high risk of stroke. It is trialled in patients with moderate risk and low risk, again producing positive outcomes. Clinicians are impressed by the "red pill's" (unknown) properties and so begin to investigate its role in the treatment of a range of other conditions, though these are chosen on an ad hoc basis as there is no underlying rationale for its use. Equally impressed by the effects of red pills, a number of pharmaceutical companies launch other versions of red pills – the magenta pill, the crimson pill, and the vermillion pill. After ten years of trials the Cochrane Collaboration Red Pill Review Group begins to conduct systematic reviews of the effectiveness of "red pills" in the treatment of patients with stroke, asthma, epilepsy, and migraine to establish the generalisable messages about the effectiveness of "red pills."