Retractions
Retraction
BMJ 2017; 358 doi: https://doi.org/10.1136/bmj.j3228 (Published 03 July 2017) Cite this as: BMJ 2017;358:j3228This article (BMJ 2002;325:1428, doi:10.1136/bmj.325.7377.1428) has been retracted by the journal following a complaint.