Title | GRADE guidelines: 5. Rating the quality of evidence--publication bias. |
Publication Type | Journal Article |
Year of Publication | 2011 |
Authors | Guyatt GH, Oxman AD, Montori V, Vist G, Kunz R, Brozek J, Alonso-Coello P, Djulbegovic B, Atkins D, Falck-Ytter Y, Williams JW, Meerpohl J, Norris SL, Akl EA, Schünemann HJ |
Journal | Journal of clinical epidemiology |
Volume | 64 |
Issue | 12 |
Pagination | 1277-82 |
Date Published | 2011 Dec |
ISSN | 1878-5921 |
Keywords | Cross-Sectional Studies; Drug Industry; Evidence-Based Medicine; Meta-Analysis as Topic; Practice Guidelines as Topic; Publication Bias; Randomized Controlled Trials as Topic; Review Literature as Topic; Statistics as Topic |
Abstract | 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. |
DOI | 10.1016/j.jclinepi.2011.01.011 |
Alternate Journal | J Clin Epidemiol |