Updates are available Correction dated 2015-09-25

Correspondence: Some general points regarding Ledberg and Wennberg, BMC Medical Research Methodology 2014 April 27;14:58

Crossref DOI link: https://doi.org/10.1186/s12874-015-0043-9

Published Online: 2015-07-07

Published Print: 2015-12

Update policy: https://doi.org/10.1007/springer_crossmark_policy