Corrections
Correction
BMJ 2020; 369 doi: https://doi.org/10.1136/bmj.m1398 (Published 07 April 2020) Cite this as: BMJ 2020;369:m1398
Article usage
Article metrics provide readers and authors with an indication of how often a specific article has been accessed month by month. It counts three formats - abstract/extract, full text and pdf. The page is updated each day.