RT Journal Article SR Electronic T1 Correction: What does expert opinion in guidelines mean? a meta-epidemiological study JF BMJ Evidence-Based Medicine JO BMJ EBM FD BMJ Publishing Group Ltd SP e110798corr1 DO 10.1136/ebmed-2017-110798corr1 YR 2017 UL http://ebm.bmj.com/content/early/2018/02/03/ebmed-2017-110798corr1.abstract AB