Rapid responses are electronic comments to the editor. They enable our users to debate issues raised in articles published on bmj.com. A rapid response is first posted online. If you need the URL (web address) of an individual response, simply click on the response headline and copy the URL from the browser window. A proportion of responses will, after editing, be published online and in the print journal as letters, which are indexed in PubMed. Rapid responses are not indexed in PubMed and they are not journal articles. The BMJ reserves the right to remove responses which are being wilfully misrepresented as published articles.
Evidence is wrong if there are counterexamples to it. This is a time honored concept by Sir Karl Popper, who was knighted for his philosophy on science. Counterexamples play an active role in correcting, limiting, or modifying all sciences except in medicine where they are ignored or dismissed as mere anecdotes.