TY - JOUR
T1 - GRADE guidelines
T2 - 5. Rating the quality of evidence - Publication bias
AU - Guyatt, Gordon H.
AU - Oxman, Andrew D.
AU - Montori, Victor Manuel
AU - Vist, Gunn
AU - Kunz, Regina
AU - Brozek, Jan
AU - Alonso-Coello, Pablo
AU - Djulbegovic, Ben
AU - Atkins, David
AU - Falck-Ytter, Yngve
AU - Williams, John W.
AU - Meerpohl, Joerg
AU - Norris, Susan L.
AU - Akl, Elie A.
AU - Schünemann, Holger J.
PY - 2011/12
Y1 - 2011/12
N2 - In the GRADE approach, randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down if a body of evidence is associated with a high risk of publication bias. Even when individual studies included in best-evidence summaries have a low risk of bias, publication bias can result in substantial overestimates of effect. Authors should suspect publication bias when available evidence comes from a number of small studies, most of which have been commercially funded. A number of approaches based on examination of the pattern of data are available to help assess publication bias. The most popular of these is the funnel plot; all, however, have substantial limitations. Publication bias is likely frequent, and caution in the face of early results, particularly with small sample size and number of events, is warranted.
AB - In the GRADE approach, randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down if a body of evidence is associated with a high risk of publication bias. Even when individual studies included in best-evidence summaries have a low risk of bias, publication bias can result in substantial overestimates of effect. Authors should suspect publication bias when available evidence comes from a number of small studies, most of which have been commercially funded. A number of approaches based on examination of the pattern of data are available to help assess publication bias. The most popular of these is the funnel plot; all, however, have substantial limitations. Publication bias is likely frequent, and caution in the face of early results, particularly with small sample size and number of events, is warranted.
KW - Conflict of interest
KW - Funnel plot
KW - GRADE
KW - Pharmaceutical industry
KW - Publication bias
KW - Quality of evidence
UR - http://www.scopus.com/inward/record.url?scp=80054759619&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80054759619&partnerID=8YFLogxK
U2 - 10.1016/j.jclinepi.2011.01.011
DO - 10.1016/j.jclinepi.2011.01.011
M3 - Article
C2 - 21802904
SN - 0895-4356
VL - 64
SP - 1277
EP - 1282
JO - Journal of Clinical Epidemiology
JF - Journal of Clinical Epidemiology
IS - 12
ER -