Kunath F, Grobe HR, Keck B, et al. Do urology journals enforce trial registration? A cross-sectional study of published trials. BMJ Open 2011;1:e000430. doi: 10.1136/bmjopen-2011-000430

In relation to an issue raised by a reader regarding some minor overlap between this paper published in BMJ Open (10.1136/bmjopen-2011-000430) and one published in Urologia Internationalis (Do journals publishing in the field of urology endorse reporting guidelines? A survey of author instructions. Kunath F, Grobe HR, Rücker G, Engehausen D, Antes G, Wullich B, Meerpohl JJ. Urol Int 2012;88:54–9. doi:10.1159/000332742. Epub 19 Nov 2011) we would like to clarify:

• Both publications are based on the same set of journal author’s instructions. However, they were evaluated separately and one after the other for the individual research questions several weeks apart. Obviously, both projects address different issues. Due to the same data sources, both publications include a minor section of text that is similar. Citation of the work published in Urologia Internationalis was unfortunately missed at the time (due to overlapping submission processes); however, the full reference is now being given here (Do journals publishing in the field of urology endorse reporting guidelines? A survey of author instructions. Kunath F, Grobe HR, Rücker G, Engehausen D, Antes G, Wullich B, Meerpohl JJ. Urol Int 2012;88:54–9. doi:10.1159/000332742. Epub 19 Nov 2011).

• Also, there is a minor discrepancy in numbers in relation to proportion of journals author’s instruction mentioning the ICMJE URM. This is a result of separate and independent assessments with a different focus (for this publication on trial registration) of the author’s instructions. We would like to point out that the discrepancy resulted from a different classification of the author’s instruction of the journals ‘European Urology’ and ‘European Urology Supplement’. For the item ‘mention of the URM’ for both journals, there was only a vague reference to the homepage of the ICMJE which lead to different classification:

  • In our first project, (Urologia internationalis with focus on the extent to which reporting guidelines are referred to in the author instructions of journals publishing in the field of urology), we assessed that in the author’s instruction of both ‘European Urology’ and ‘European Urology Supplement’ the URM were only indirectly mentioned by referring to the URL of the ICMJE in relation to trial registration.

  • In our second project (BMJ Open with focus on trial registration), based on very thorough evaluation of the respective text sections we concluded that in the author’s instructions of ‘European Urology’, the URM were indirectly mentioned by referring to the URL of the ICMJE in relation to conflict of interest; and that in the author’s instruction of ‘European Urology Supplement’ the URM were indirectly mentioned by referring to the URL of the ICMJE in relation to reference style.

These slightly divergent classifications highlight the fact that guidance in author’s instructions is not always very clear. Given that online author’s instructions of both journals have been updated since our evaluation, we cannot definitively decide now whether the URL was referred to in a sentence or paragraph on trial registration only, or conflict of interest only, or reference style only, or most likely a section addressing a combination of these issues.