Erratum
Unfortunately, the original version of this article [1] contained an error.
Under ‘Study 2’, the text read: “The first search was the same as in the Study 1, except that we screened all articles that were co-cited in more than 1 % of the citing articles.”
However, this sentence should have also included articles that were “co-cited more than once”, to read: “The first search was the same as in the Study 1, except that we screened all articles that were co-cited more than once and co-cited in more than 1 % of the citing articles.”
We apologise for this error.
Footnotes
The online version of the original article can be found under doi:10.1186/s12874-015-0077-z.
References
- 1.Janssens ACJW, Gwinn M. BMC Med. Res. Methodol. 2015;15:84. doi:10.1186/s12874-015-0077-z. [DOI] [PMC free article] [PubMed]